TY - JOUR A1 - Hermanussen, Michael A1 - Assmann, Christian A1 - Staub, K. A1 - Groth, Detlef T1 - Monte Carlo simulation of body height in a spatial network JF - European journal of clinical nutrition N2 - BACKGROUND/OBJECTIVES: Recent evidence suggests clustering of human body height. We want to assess the consequences of connectedness in a spatial network on height clustering in an artificial society. SUBJECTS/METHODS: We used an agent-based computer modelling technique (Monte Carlo simulation) and compared simulated height in a spatial network with characteristics of the observed geographic height distribution of three historic cohorts of Swiss military conscripts (conscripted in 1884-1891; 1908-1910; and 2004-2009). RESULTS: Conscript height shows several characteristic features: (1) height distributions are overdispersed. (2) Conscripts from districts with direct inter-district road connections tend to be similar in height. (3) Clusters of tall and clusters of short stature districts vary over time. Autocorrelations in height between late 19th and early 21st century districts are low. (4) Mean district height depends on the number of connecting roads and on the number of conscripts per district. Using Monte Carlo simulation, we were able to generate these natural characteristics in an artificial society. Already 5% height information from directly connected districts is sufficient to simulate the characteristics of natural height distribution. Very similar observations in regular rectangular networks indicate that the characteristics of Swiss conscript height distributions do not so much result from the particular Swiss geography but rather appear to be general features of spatial networks. CONCLUSIONS: Spatial connectedness can affect height clustering in an artificial society, similar to that seen in natural cohorts of military conscripts, and strengthen the concept of connectedness being involved in the regulation of human height. Y1 - 2016 U6 - https://doi.org/10.1038/ejcn.2016.45 SN - 0954-3007 SN - 1476-5640 VL - 70 SP - 671 EP - 678 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Heinze, Johannes A1 - Sitte, Mario A1 - Schindhelm, Anne A1 - Wright, J. A1 - Joshi, Jasmin Radha T1 - Plant-soil feedbacks: a comparative study on the relative importance of soil feedbacks in the greenhouse versus the field JF - Oecologia N2 - Interactions between plants and soil microorganisms influence individual plant performance and thus plant-community composition. Most studies on such plant-soil feedbacks (PSFs) have been performed under controlled greenhouse conditions, whereas no study has directly compared PSFs under greenhouse and natural field conditions. We grew three grass species that differ in local abundance in grassland communities simultaneously in the greenhouse and field on field-collected soils either previously conditioned by these species or by the general grassland community. As soils in grasslands are typically conditioned by mixes of species through the patchy and heterogeneous plant species’ distributions, we additionally compared the effects of species-specific versus non-specific species conditioning on PSFs in natural and greenhouse conditions. In almost all comparisons PSFs differed between the greenhouse and field. In the greenhouse, plant growth in species-specific and non-specific soils resulted in similar effects with neutral PSFs for the most abundant species and positive PSFs for the less abundant species. In contrast, in the field all grass species tested performed best in non-specific plots, whereas species-specific PSFs were neutral for the most abundant and varied for the less abundant species. This indicates a general beneficial effect of plant diversity on PSFs in the field. Controlled greenhouse conditions might provide valuable insights on the nominal effects of soils on plants. However, the PSFs observed in greenhouse conditions may not be the determining drivers in natural plant communities where their effects may be overwhelmed by the diversity of abiotic and biotic above- and belowground interactions in the field. KW - Grassland KW - Plant performance KW - Experimental environment KW - Community assembly KW - Plant diversity Y1 - 2016 U6 - https://doi.org/10.1007/s00442-016-3591-8 SN - 0029-8549 SN - 1432-1939 VL - 181 SP - 559 EP - 569 PB - Springer CY - New York ER - TY - JOUR A1 - Heinze, Johannes A1 - Gensch, Sabine A1 - Weber, Ewald A1 - Joshi, Jasmin Radha T1 - Soil temperature modifies effects of soil biota on plant growth JF - Journal of plant ecology N2 - Aims Plants directly and indirectly interact with many abiotic and biotic soil components. Research so far mostly focused on direct, individual abiotic or biotic effects on plant growth, but only few studies tested the indirect effects of abiotic soil factors on plant growth. Therefore, we investigated how abiotic soil conditions affect plant performance, via changes induced by soil biota. Methods In a full-factorial experiment, we grew the widespread grass Dactylis glomerata either with or without soil biota and investigated the impact of soil temperature, fertility and moisture on the soil biota effects on plant growth. We measured biomass production, root traits and colonization by arbuscular mycorrhizal fungi as well as microbial respiration. Important Findings We found significant interaction effects between abiotic soil conditions and soil biota on plant growth for fertility, but especially for soil temperature, as an increase of 10 degrees C significantly changed the soil biota effects on plant growth from positive to neutral. However, if tested individually, an increase in soil temperature and fertility per se positively affected plant biomass production, whereas soil biota per se did not affect overall plant growth, but both influenced root architecture. By affecting soil microbial activity and root architecture, soil temperature might influence both mutualistic and pathogenic interactions between plants and soil biota. Such soil temperature effects should be considered in soil feedback studies to ensure greater transferability of results from artificial and experimental conditions to natural environmental conditions. KW - plant-soil interaction KW - soil biota KW - abiotic soil factors KW - root traits KW - plant growth Y1 - 2016 U6 - https://doi.org/10.1093/jpe/rtw097 SN - 1752-9921 SN - 1752-993X VL - 10 SP - 808 EP - 821 PB - Oxford Univ. Press CY - Oxford ER - TY - THES A1 - Heinze, Johannes T1 - The impact of soil microbiota on plant species performance and diversity in semi-natural grasslands Y1 - 2016 ER - TY - THES A1 - Heinle, Karolin T1 - Identifizierung von Kohlenhydratbindungsstellen in β-Helix-Proteinen Y1 - 2016 ER - TY - JOUR A1 - Heim, Olga A1 - Schröder, Assja A1 - Eccard, Jana A1 - Jung, Kirsten A1 - Voigt, Christian C. T1 - Seasonal activity patterns of European bats above intensively used farmland JF - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters N2 - Bats are top insect predators on farmland, yet they suffer from intensive farmland management. Here, we evaluated the seasonal activity patterns of European bats above large, arable fields and compared these patterns between ecologically distinct bat species. Using repeated passive acoustic monitoring on a total of 93 arable fields in 2 years in Brandenburg, Germany, we surveyed the activity of different bat species between early spring and autumn. We then used generalized additive mixed models to describe and compare the seasonal bat activity patterns between bat categories, which were build based on the affiliation to a functional group and migratory class, while controlling for local weather conditions. In general, the affiliation to a bat category in interaction with the season in addition to cloud cover and ambient air temperature explained a major part of bat activity. The season was also an important factor for the foraging activity of open-space specialists such as Nyctalus noctula but showed only a weak effect on species such as Pipistreilus nathusii which are adapted to edge-space habitats. Across the seasons, habitat use intensity was high during the period of swarming and migration and low during the energy demanding period of lactation. Seasonal patterns in foraging activity showed that open-space specialists foraged more intensively above agricultural fields during the migration period, while edge-space specialists foraged also during the energy demanding period of lactation. We conclude that the significant seasonal fluctuations in bat activity and significant differences between bat categories in open agricultural landscapes should be taken into consideration when designing monitoring schemes and management plans for bat species in regions dominated by agriculture. Also, management plans should be directed to improve the conditions on arable land especially for bat species which would be classified as narrow-space foragers such as Myotis species. (C) 2016 Elsevier B.V. All rights reserved. KW - Agricultural intensification KW - Seasonality KW - European bat species KW - Functional bat group KW - Migration KW - AgroScapeLabs Y1 - 2016 U6 - https://doi.org/10.1016/j.agee.2016.09.002 SN - 0167-8809 SN - 1873-2305 VL - 233 SP - 130 EP - 139 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Havinga, Reinout A1 - Kool, Anneleen A1 - Achille, Frederic A1 - Bavcon, Joze A1 - Berg, Christian A1 - Bonomi, Costantino A1 - Burkart, Michael A1 - De Meyere, Dirk A1 - Havstrom, Mats A1 - Kessler, Paul A1 - Knickmann, Barbara A1 - Koester, Nils A1 - Martinez, Remy A1 - Ostgaard, Havard A1 - Ravnjak, Blanka A1 - Scheen, Anne-Cathrine A1 - Smith, Pamela A1 - Smith, Paul A1 - Socher, Stephanie A. A1 - Vange, Vibekke T1 - The Index Seminum: Seeds of change for seed exchange JF - Taxon N2 - Botanic gardens have been exchanging seeds through seed catalogues for centuries. In many gardens, these catalogues remain an important source of plant material. Living collections have become more relevant for genetic analysis and derived research, since genomics of non-model organisms heavily rely on living material. The range of species that is made available annually on all seed lists combined, provides an unsurpassed source of instantly accessible plant material for research collections. Still, the Index Seminum has received criticism in the past few decades. The current exchange model dictates that associated data is manually entered into each database. The amount of time involved and the human errors occurring in this process are difficult to justify when the data was initially produced as a report from another database. The authors propose that an online marketplace for seed exchange should be established, with enhanced search possibilities and downloadable accession data in a standardised format. Such online service should preferably be supervised and coordinated by Botanic Gardens Conservation International (BGCI). This manuscript is the outcome of a workshop on July 9th, 2015, at the European botanic gardens congress "Eurogard VII" in Paris, where the first two authors invited members of the botanic garden community to discuss how the anachronistic Index Seminum can be transformed into an improved and modern tool for seed exchange. KW - database KW - Index Seminum KW - information technology KW - living collections management KW - Nagoya-protocol KW - seed exchange Y1 - 2016 U6 - https://doi.org/10.12705/652.9 SN - 0040-0262 SN - 1996-8175 VL - 65 SP - 333 EP - 336 PB - International Association for Plant Taxonomy CY - Bratislava ER - TY - JOUR A1 - Hassan, Rabeay Y. A. A1 - Wollenberger, Ursula T1 - Mediated bioelectrochemical system for biosensing the cell viability of Staphylococcus aureus JF - Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry and Analusis N2 - Staphylococcus aureus is one of the most dangerous human pathogens and is the cause of numerous illnesses ranging from moderate skin infections to life-threatening diseases. Despite advances made in identifying microorganisms, rapid detection methods for the viability of bacteria are still missing. Here, we report a rapid electrochemical assay for cell viability combining the use of double redox mediators and multiwall carbon nanotubes-screen printed electrodes (MWCNTs-SPE), ferricyanide (FCN) and 2,6-dichlorophenolindophenol (DCIP), which served as electron shuttle to enable the bacterial-electrode communications. The current originating from the metabolically active cells was recorded for probing the activity of the intracellular redox centers. Blocking of the respiratory chain pathways with electron transfer inhibitors demonstrated the involvement of the electron transport chain in the reaction. A good correlation between the number of the metabolically active cells and the current was obtained. The proposed assay has been exploited for monitoring cell proliferation of S. aureus during the growth. The sensitivity of the detection method reached 0.1 OD600. Therefore, the technique described is promising for estimating the cell number, measuring the cell viability, and probing intracellular redox center(s). KW - Microbial electrochemistry KW - Pathogenic detection KW - Probing living Staphylococcus aureus KW - CNTs-based screen printed electrodes Y1 - 2016 U6 - https://doi.org/10.1007/s00216-015-9134-z SN - 1618-2642 SN - 1618-2650 VL - 408 SP - 579 EP - 587 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Hartmann, Tobias A1 - Schrapers, Peer A1 - Utesch, Tillmann A1 - Nimtz, Manfred A1 - Rippers, Yvonne A1 - Dau, Holger A1 - Mroginski, Maria Andrea A1 - Haumann, Michael A1 - Leimkühler, Silke T1 - The Molybdenum Active Site of Formate Dehydrogenase Is Capable of Catalyzing C-H Bond Cleavage and Oxygen Atom Transfer Reactions JF - Biochemistry N2 - Formate dehydrogenases (FDHs) are capable of performing the reversible oxidation of formate and are enzymes of great interest for fuel cell applications and for the production of reduced carbon compounds as energy sources from CO2. Metal containing FDHs in general contain a highly conserved active site, comprising a molybdenum (or tungsten) center coordinated by two molybdopterin guanine dinucleotide molecules, a sulfido and a (seleno-)cysteine ligand, in addition to a histidine and arginine residue in the second coordination sphere. So far, the role of these amino acids in catalysis has not been studied in detail, because of the lack of suitable expression systems and the lability or oxygen sensitivity of the enzymes. Here, the roles of these active site residues is revealed using the Mo-containing FDH from Rhodobacter capsulatus. Our results show that the cysteine ligand at the Mo ion is displaced by the formate substrate during the reaction, the arginine has a direct role in substrate binding and stabilization, and the histidine elevates the pK(a) of the active site cysteine. We further found that in addition to reversible formate oxidation, the enzyme is further capable of reducing nitrate to nitrite. We propose a mechanistic scheme that combines both functionalities and provides important insights into the distinct mechanisms of C-H bond cleavage and oxygen atom transfer catalyzed by formate dehydrogenase. Y1 - 2016 U6 - https://doi.org/10.1021/acs.biochem.6b00002 SN - 0006-2960 VL - 55 SP - 2381 EP - 2389 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Hartmann, Bianca A1 - Wai, Timothy A1 - Hu, Hao A1 - MacVicar, Thomas A1 - Musante, Luciana A1 - Fischer-Zirnsak, Björn A1 - Stenzel, Werner A1 - Gräf, Ralph A1 - van den Heuvel, Lambert A1 - Ropers, Hans-Hilger A1 - Wienker, Thomas F. A1 - Hübner, Christoph A1 - Langer, Thomas A1 - Kaindl, Angela M. T1 - Homozygous YME1L1 Mutation Causes Mitochondriopathy with Optic Atrophy and Mitochondrial Network Fragmentation JF - eLife N2 - Mitochondriopathies often present clinically as multisystemic disorders of primarily high-energy consuming organs. Assembly, turnover, and surveillance of mitochondrial proteins are essential for mitochondrial function and a key task of AAA family members of metalloproteases. We identified a homozygous mutation in the nuclear encoded mitochondrial escape 1-like 1 gene YME1L1, member of the AAA protease family, as a cause of a novel mitochondriopathy in a consanguineous pedigree of Saudi Arabian descent. The homozygous missense mutation, located in a highly conserved region in the mitochondrial pre-sequence, inhibits cleavage of YME1L1 by the mitochondrial processing peptidase, which culminates in the rapid degradation of YME1L1 precursor protein. Impaired YME1L1 function causes a proliferation defect and mitochondrial network fragmentation due to abnormal processing of OPA1. Our results identify mutations in YME1L1 as a cause of a mitochondriopathy with optic nerve atrophy highlighting the importance of YME1L1 for mitochondrial functionality in humans. KW - YME1L1 KW - mitochondriopathy KW - intellectual disability KW - optic atrophy KW - OPA1 KW - mitochondrial fragmentation Y1 - 2016 U6 - https://doi.org/10.7554/eLife.16078 SN - 2050-084X VL - 5 SP - 1156 EP - 1165 PB - eLife Sciences Publications CY - Cambridge ER - TY - JOUR A1 - Hanke-Gogokhia, Christin A1 - Zhang, Houbin A1 - Frederick, Jeanne M. A1 - Baehr, Wolfgang ED - Rickman, CB ED - LaVail, MM ED - Anderson, RE ED - Grimm, C ED - Hollyfield, J ED - Ash, J T1 - The Function of Arf-like Proteins ARL2 and ARL3 in Photoreceptors JF - Retinal Degenerative Diseases : Mechanisms and Experimental Therapy N2 - Arf-like proteins (ARLs) are ubiquitously expressed small G proteins of the RAS superfamily. In photoreceptors, ARL2 and ARL3 participate in the trafficking of lipidated membrane-associated proteins and colocalize in the inner segment with UNC119A and PDE delta. UNC119A and PDE delta are acyl-and prenyl-binding proteins, respectively, involved in trafficking of acylated (transducin-alpha subunit, nephrocystin NPHP3) and prenylated proteins (GRK1, PDE6). Germline Arl3 knockout mice do not survive beyond postnatal day 21 and display ciliary defects in multiple organs (kidney, liver and pancreas) as well as retinal degeneration. Conditional knockouts will be necessary to delineate mechanisms of protein transport in retina disease. KW - Arf-like protein 3 (ARL3) KW - Arf-like protein 2 (ARL2) KW - Phosphodiesterase delta-subunit (PDE delta) KW - unc-119 homolog (C. elegans) (UNC119A) KW - Retinitis pigmentosa protein 2 (RP2) KW - Rod photoreceptor Y1 - 2016 SN - 978-3-319-17121-0; 978-3-319-17120-3 U6 - https://doi.org/10.1007/978-3-319-17121-0_87 SN - 0065-2598 VL - 854 SP - 655 EP - 661 PB - Springer International Publishing AG CY - Cham ER - TY - JOUR A1 - Hanke-Gogokhia, Christin A1 - Wu, Zhijian A1 - Gerstner, Cecilia D. A1 - Frederick, Jeanne M. A1 - Zhang, Houbin A1 - Baehr, Wolfgang T1 - Arf-like Protein 3 (ARL3) Regulates Protein Trafficking and Ciliogenesis in Mouse Photoreceptors JF - The journal of biological chemistry N2 - Arf-like protein 3 (ARL3) is a ubiquitous small GTPase expressed in ciliated cells of plants and animals. Germline deletion of Arl3 in mice causes multiorgan ciliopathy reminiscent of Bardet-Biedl or Joubert syndromes. As photoreceptors are elegantly compartmentalized and have cilia, we probed the function of ARL3 (ADP-ribosylation factor (Arf)-like 3 protein) by generating rod photoreceptor-specific (prefix (rod)) and retina-specific (prefix (ret)) Arl3 deletions. In predegenerate (rod)Arl3(-/-) mice, lipidated phototransduction proteins showed trafficking deficiencies, consistent with the role of ARL3 as a cargo displacement factor for lipid-binding proteins. By contrast, (ret)Arl3(-/-) rods and cones expressing Cre recombinase during embryonic development formed neither connecting cilia nor outer segments and degenerated rapidly. Absence of cilia infers participation of ARL3 in ciliogenesis and axoneme formation. Ciliogenesis was rescued, and degeneration was reversed in part by subretinal injection of adeno-associated virus particles expressing ARL3-EGFP. The conditional knock-out phenotypes permitted identification of two ARL3 functions, both in the GTP-bound form as follows: one as a regulator of intraflagellar transport participating in photoreceptor ciliogenesis and the other as a cargo displacement factor transporting lipidated protein to the outer segment. Surprisingly, a farnesylated inositol polyphosphate phosphatase only trafficked from the endoplasmic reticulum to the Golgi, thereby excluding it from a role in photoreceptor cilia physiology. KW - animal model KW - gene knock-out KW - lipid-binding protein KW - photoreceptor KW - protein trafficking (Golgi) KW - retinal degeneration Y1 - 2016 U6 - https://doi.org/10.1074/jbc.M115.710954 SN - 0021-9258 SN - 1083-351X VL - 291 SP - 7142 EP - 7155 PB - American Society for Biochemistry and Molecular Biology CY - Bethesda ER - TY - THES A1 - Hanke-Gogokhia, Christin T1 - Small GTPase ARL3-GTP is key molecule in transition zone formation and trafficking of ciliary cargo in mouse photoreceptors Y1 - 2016 ER - TY - GEN A1 - Hanack, Katja A1 - Schloer, Anja A1 - Holzloehner, Pamela A1 - Listek, Martin A1 - Bauer, Cindy A1 - Butze, Monique A1 - Micheel, Burkhard A1 - Hentschel, Christian A1 - Sowa, Mandy A1 - Roggenbuck, Dirk A1 - Schierack, Peter A1 - Fuener, Jonas A1 - Schliebs, Erik A1 - Goihl, Alexander A1 - Reinhold, Dirk T1 - Camelid nanobodies specific to human pancreatic glycoprotein 2 T2 - The journal of immunology N2 - Pancreatic secretory zymogen-granule membrane glycoprotein 2 (GP2) has been identified to be a major autoantigenic target in Crohn’s disease patients. It was discussed recently that a long and a short isoform of GP2 exists whereas the short isoform is often detected by GP2-specific autoantibodies. In the outcome of inflammatory bowel diseases, these GP2-specific autoantibodies are discussed as new serological markers for diagnosis and therapeutic monitoring. To investigate this further, camelid nanobodies were generated by phage display and selected against the short isoform of GP2 in order to isolate specific tools for the discrimination of both isoforms. Nanobodies are single domain antibodies derived from camelid heavy chain only antibodies and characterized by a high stability and solubility. The selected candidates were expressed, purified and validated regarding their binding properties in different enzyme-linked immunosorbent assays formats, immunofluorescence, immunohistochemistry and surface plasmon resonance spectroscopy. Four different nanobodies could be selected whereof three recognize the short isoform of GP2 very specifically and one nanobody showed a high binding capacity for both isoforms. The KD values measured for all nanobodies were between 1.3 nM and 2.3 pM indicating highly specific binders suitable for the application as diagnostic tool in inflammatory bowel disease. Y1 - 2016 SN - 0022-1767 SN - 1550-6606 VL - 196 SP - 313 EP - 328 PB - American Assoc. of Immunologists CY - Bethesda ER - TY - JOUR A1 - Han, Xiao Xia A1 - Li, Junbo A1 - Öner, Ibrahim Halil A1 - Zhao, Bing A1 - Leimkühler, Silke A1 - Hildebrandt, Peter A1 - Weidinger, Inez M. T1 - Nickel electrodes as a cheap and versatile platform for studying structure and function of immobilized redox proteins JF - Analytica chimica acta : an international journal devoted to all branches of analytical chemistry N2 - Practical use of many bioelectronic and bioanalytical devices is limited by the need of expensive materials and time consuming fabrication. Here we demonstrate the use of nickel electrodes as a simple and cheap solid support material for bioelectronic applications. The naturally nanostructured electrodes showed a surprisingly high electromagnetic surface enhancement upon light illumination such that immobilization and electron transfer reactions of the model redox proteins cytochrome b(5) (Cyt b(5)) and cytochrome c (Cyt c) could be followed via surface enhanced resonance Raman spectroscopy. It could be shown that the nickel surface, when used as received, promotes a very efficient binding of the proteins upon preservation of their native structure. The immobilized redox proteins could efficiently exchange electrons with the electrode and could even act as an electron relay between the electrode and solubilized myoglobin. Our results open up new possibility for nickel electrodes as an exceptional good support for bioelectronic devices and biosensors on the one hand and for surface enhanced spectroscopic investigations on the other hand. (C) 2016 Elsevier B.V. All rights reserved. KW - Ni electrodes KW - Redox proteins KW - Surface enhanced Raman spectroscopy KW - Electron relay KW - Biocompatibility KW - Electron transfer Y1 - 2016 U6 - https://doi.org/10.1016/j.aca.2016.08.053 SN - 0003-2670 SN - 1873-4324 VL - 941 SP - 35 EP - 40 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Haack, Timm A1 - Abdelilah-Seyfried, Salim T1 - The force within: endocardial development, mechanotransduction and signalling during cardiac morphogenesis JF - Development : Company of Biologists N2 - Endocardial cells are cardiac endothelial cells that line the interior of the heart tube. Historically, their contribution to cardiac development has mainly been considered from a morphological perspective. However, recent studies have begun to define novel instructive roles of the endocardium, as a sensor and signal transducer of biophysical forces induced by blood flow, and as an angiocrine signalling centre that is involved in myocardial cellular morphogenesis, regeneration and reprogramming. In this Review, we discuss how the endocardium develops, how endocardial-myocardial interactions influence the developing embryonic heart, and how the dysregulation of blood flowresponsive endocardial signalling can result in pathophysiological changes. KW - Endocardium KW - Cardiac development KW - Hemodynamics KW - Bmp KW - Kruppel-like factor 2 KW - Vegf KW - Mechanotransduction KW - Zebrafish KW - Mouse Y1 - 2016 U6 - https://doi.org/10.1242/dev.131425 SN - 0950-1991 SN - 1477-9129 VL - 143 SP - 373 EP - 386 PB - Company of Biologists Limited CY - Cambridge ER - TY - JOUR A1 - Guo, Tong A1 - Lohmann, Dirk A1 - Ratzmann, Gregor A1 - Tietjen, Britta T1 - Response of semi-arid savanna vegetation composition towards grazing along a precipitation gradient-The effect of including plant heterogeneity into an ecohydrological savanna model JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - Ecohydrological models of savanna rangeland systems typically aggregate plant species to very broad plant functional types (PFTs), which are characterized by their trait combinations. However, neglecting trait variability within modelled PFTs may hamper our ability to understand the effects of climate or land use change on vegetation composition and thus on ecosystem processes. In this study we extended and parameterized the ecohydrological savanna model EcoHyD, which originally considered only three broad PFTs (perennial grasses, annuals and shrubs). We defined several sub-types of perennial grasses (sub-PFTs) to assess the effect of environmental conditions on vegetation composition and ecosystem functioning. These perennial sub-PFTs are defined by altering distinct trait values based on a trade-off approach for (i) the longevity of plants and (ii) grazing-resistance. We find that increasing grazing intensity leads to a dominance of the fast-growing and short-lived perennial grass type as well as a dominance of the poorly palatable grass type. Increasing precipitation dampens the magnitude of grazing-induced shifts between perennial grass types. The diversification of perennial grass PFTs generally increases the total perennial grass cover and ecosystem water use efficiency, but does not protect the community from shrub encroachment. We thus demonstrate that including trait heterogeneity into ecosystem models will allow for an improved representation of ecosystem responses to environmental change in savannas. This will help to better assess how ecosystem functions might be impacted under future conditions. (C) 2016 Elsevier B.V. All rights reserved. KW - Plant functional types KW - Trait heterogeneity KW - Rangeland management KW - Precipitation gradient KW - Livestock KW - Ecosystem functioning Y1 - 2016 U6 - https://doi.org/10.1016/j.ecolmodel.2016.01.004 SN - 0304-3800 SN - 1872-7026 VL - 325 SP - 47 EP - 56 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Guardado-Calvo, Pablo A1 - Bignon, Eduardo A. A1 - Stettner, Eva A1 - Jeffers, Scott Allen A1 - Perez-Vargas, Jimena A1 - Pehau-Arnaudet, Gerard A1 - Tortoric, M. Alejandra A1 - Jestin, Jean-Luc A1 - England, Patrick A1 - Tischler, Nicole D. A1 - Rey, Felix A. T1 - Mechanistic Insight into Bunyavirus-Induced Membrane Fusion from Structure-Function Analyses of the Hantavirus Envelope Glycoprotein Gc JF - PLoS Pathogens N2 - Hantaviruses are zoonotic viruses transmitted to humans by persistently infected rodents, giving rise to serious outbreaks of hemorrhagic fever with renal syndrome (HFRS) or of hantavirus pulmonary syndrome (HPS), depending on the virus, which are associated with high case fatality rates. There is only limited knowledge about the organization of the viral particles and in particular, about the hantavirus membrane fusion glycoprotein Gc, the function of which is essential for virus entry. We describe here the X-ray structures of Gc from Hantaan virus, the type species hantavirus and responsible for HFRS, both in its neutral pH, monomeric pre-fusion conformation, and in its acidic pH, trimeric post-fusion form. The structures confirm the prediction that Gc is a class II fusion protein, containing the characteristic beta-sheet rich domains termed I, II and III as initially identified in the fusion proteins of arboviruses such as alpha-and flaviviruses. The structures also show a number of features of Gc that are distinct from arbovirus class II proteins. In particular, hantavirus Gc inserts residues from three different loops into the target membrane to drive fusion, as confirmed functionally by structure-guided mutagenesis on the HPS-inducing Andes virus, instead of having a single "fusion loop". We further show that the membrane interacting region of Gc becomes structured only at acidic pH via a set of polar and electrostatic interactions. Furthermore, the structure reveals that hantavirus Gc has an additional N-terminal "tail" that is crucial in stabilizing the post-fusion trimer, accompanying the swapping of domain III in the quaternary arrangement of the trimer as compared to the standard class II fusion proteins. The mechanistic understandings derived from these data are likely to provide a unique handle for devising treatments against these human pathogens. Y1 - 2016 U6 - https://doi.org/10.1371/journal.ppat.1005813 SN - 1553-7366 SN - 1553-7374 VL - 12 SP - 153 EP - 166 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Grzesiuk, Malgorzata A1 - Wacker, Alexander A1 - Spijkerman, Elly T1 - Photosynthetic sensitivity of phytoplankton to commonly used pharmaceuticals and its dependence on cellular phosphorus status JF - Ecotoxicology N2 - Recently pharmaceuticals have become significant environmental pollutants in aquatic ecosystems, that could affect primary producers such as microalgae. Here we analyzed the effect of pharmaceuticals on the photosynthesis of microalgae commonly found in freshwater-two species of Chlorophyceae and a member of the Eustigmatophyceae, via PAM fluorometry. As pharmaceuticals, three medicines often consumed in households were chosen: (i) fluoxetine, an antidepressant, (ii) propranolol, a beta-blocker and (iii) ibuprofen, an anti-inflammatory and analgesic medicine. The EC50 for the quantum yield of photosystem II in phytoplankton acclimated to inorganic phosphorus (P-i)-replete and P-i-limited conditions was estimated. Acute toxicity experiments over a 5 h exposure revealed that Nannochloropsis limnetica was the least sensitive to pharmaceuticals in its photosynthetic yield out of all species tested. Although the estimation of sub-lethal effects can be vital in contrast to that of LC(50)s, the EC50 values in all species and for all medicines were orders of magnitude higher than concentrations found in polluted surface water. Chlamydomonas reinhardtii was the most sensitive to fluoxetine (EC50 of 1.6 mg L-1), and propranolol (EC50 of 3 mg L-1). Acutodesmus obliquus was most sensitive to ibuprofen (EC50 of 288 mg L-1). Additionally, the sensitivity to the pharmaceuticals changed under a P-i-limitation; the green algae became less sensitive to fluoxetine and propranolol. In contrast, P-i-limited algal species were more sensitive to ibuprofen. Our results suggest that the sensitivity of algae to pharmaceuticals is (i) highly compound- and species-specific and (ii) dependent on the cellular P status. KW - Freshwater algae KW - Medicine KW - EC50 KW - PAM fluorometry KW - Tolerance Y1 - 2016 U6 - https://doi.org/10.1007/s10646-016-1628-8 SN - 0963-9292 SN - 1573-3017 VL - 25 SP - 697 EP - 707 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Großart, Hans-Peter A1 - Wurzbacher, Christian A1 - James, Timothy Y. A1 - Kagami, Maiko T1 - Discovery of dark matter fungi in aquatic ecosystems demands a reappraisal of the phylogeny and ecology of zoosporic fungi JF - Fungal ecology N2 - Our knowledge of zoosporic fungal phylogeny, physiology, and ecological functions, in particular their role in aquatic food web dynamics and biogeochemistry, is limited. The recent discovery of numerous dark matter fungi (DMF), i.e., uncultured and poorly known taxa belonging to early diverging branches of the fungal tree (namely the Rozellomycota and Chytridiomycota) calls for reconsideration of the phylogeny and ecology of zoosporic fungi. In this opinion paper, we summarize the exploration of new, recently discovered lineages of DMF and their implications for the ecology, evolution, and biogeography of the rapidly growing fungal tree. We also discuss possible ecological roles of zoosporic fungi in relation to recent methodological developments including single cell genomics and cultivation efforts. Finally, we suggest linking explorative with experimental research to gain deeper insights into the physiology and ecological functioning of zoosporic fungi DMF in aquatic habitats. (C) 2015 Elsevier Ltd and The British Mycological Society. All rights reserved. KW - Dark matter fungi KW - Zoosporic fungi KW - Fungal tree KW - Chytridiomycota KW - Rozellomycota KW - Fungal physiology and ecology KW - Aquatic habitats Y1 - 2016 U6 - https://doi.org/10.1016/j.funeco.2015.06.004 SN - 1754-5048 SN - 1878-0083 VL - 19 SP - 28 EP - 38 PB - Elsevier CY - Oxford ER -