@misc{ZurellElithSchroederEsselbach2012,
  author    = {Zurell, Damaris and Elith, Jane and Schr{\"o}der-Esselbach, Boris},
  title     = {Predicting to new environments tools for visualizing model behaviour and impacts on mapped distributions},
  series = {Diversity \& distributions : a journal of biological invasions and biodiversity},
  volume    = {18},
  journal   = {Diversity \& distributions : a journal of biological invasions and biodiversity},
  number    = {6},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1366-9516},
  doi       = {10.1111/j.1472-4642.2012.00887.x},
  pages     = {628 -- 634},
  year      = {2012},
  abstract  = {Data limitations can lead to unrealistic fits of predictive species distribution models (SDMs) and spurious extrapolation to novel environments. Here, we want to draw attention to novel combinations of environmental predictors that are within the sampled range of individual predictors but are nevertheless outside the sample space. These tend to be overlooked when visualizing model behaviour. They may be a cause of differing model transferability and environmental change predictions between methods, a problem described in some studies but generally not well understood. We here use a simple simulated data example to illustrate the problem and provide new and complementary visualization techniques to explore model behaviour and predictions to novel environments. We then apply these in a more complex real-world example. Our results underscore the necessity of scrutinizing model fits, ecological theory and environmental novelty.},
  language  = {en}
}
@article{ZuoGandhiArndtetal.2012,
  author    = {Zuo, Zhili and Gandhi, Neha S. and Arndt, Katja Maren and Mancera, Ricardo L.},
  title     = {Free energy calculations of the interactions of c-Jun-based synthetic peptides with the c-Fos protein},
  series = {Biopolymers},
  volume    = {97},
  journal   = {Biopolymers},
  number    = {11},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0006-3525},
  doi       = {10.1002/bip.22099},
  pages     = {899 -- 909},
  year      = {2012},
  abstract  = {The c-Fosc-Jun complex forms the activator protein 1 transcription factor, a therapeutic target in the treatment of cancer. Various synthetic peptides have been designed to try to selectively disrupt the interaction between c-Fos and c-Jun at its leucine zipper domain. To evaluate the binding affinity between these synthetic peptides and c-Fos, polarizable and nonpolarizable molecular dynamics (MD) simulations were conducted, and the resulting conformations were analyzed using the molecular mechanics generalized Born surface area (MM/GBSA) method to compute free energies of binding. In contrast to empirical and semiempirical approaches, the estimation of free energies of binding using a combination of MD simulations and the MM/GBSA approach takes into account dynamical properties such as conformational changes, as well as solvation effects and hydrophobic and hydrophilic interactions. The predicted binding affinities of the series of c-Jun-based peptides targeting the c-Fos peptide show good correlation with experimental melting temperatures. This provides the basis for the rational design of peptides based on internal, van der Waals, and electrostatic interactions.},
  language  = {en}
}
@article{ZiegeHennigeSchulzMueckschetal.2012,
  author    = {Ziege, Madlen and Hennige-Schulz, Carmen and Muecksch, Frauke and Bierbach, David and Tiedemann, Ralph and Streit, Bruno and Plath, Martin},
  title     = {A comparison of two methods to assess audience-induced changes in male mate choice},
  series = {Current zoology},
  volume    = {58},
  journal   = {Current zoology},
  number    = {1},
  publisher = {Current Zoology},
  address   = {Beijing},
  issn      = {1674-5507},
  pages     = {84 -- 94},
  year      = {2012},
  abstract  = {Multidirectional communicative interactions in social networks can have a profound effect on mate choice behavior. Male Atlantic molly Poecilia mexicana exhibit weaker mating preferences when an audience male is presented. This could be a male strategy to reduce sperm competition risk: interacting more equally with different females may be advantageous because rivals might copy mate choice decisions. In line with this hypothesis, a previous study found males to show a strong audience effect when being observed while exercising mate choice, but not when the rival was presented only before the choice tests. Audience effects on mate choice decisions have been quantified in poeciliid fishes using association preference designs, but it remains unknown if patterns found from measuring association times translate into actual mating behavior. Thus, we created five audience treatments simulating different forms of perceived sperm competition risk and determined focal males' mating preferences by scoring pre-mating (nipping) and mating behavior (gonopodial thrusting). Nipping did not reflect the pattern that was found when association preferences were measured, while a very similar pattern was uncovered in thrusting behavior. The strongest response was observed when the audience could eavesdrop on the focal male's behavior. A reduction in the strength of focal males' preferences was also seen after the rival male had an opportunity to mate with the focal male's preferred mate. In comparison, the reduction of mating preferences in response to an audience was greater when measuring association times than actual mating behavior. While measuring direct sexual interactions between the focal male and both stimulus females not only the male's motivational state is reflected but also females' behavior such as avoidance of male sexual harassment.},
  language  = {en}
}
@article{ZhangFedyuninKirchneretal.2012,
  author    = {Zhang, Gong and Fedyunin, Ivan and Kirchner, Sebastian and Xiao, Chuanle and Valleriani, Angelo and Ignatova, Zoya},
  title     = {FANSe: an accurate algorithm for quantitative mapping of large scale sequencing reads},
  series = {Nucleic acids research},
  volume    = {40},
  journal   = {Nucleic acids research},
  number    = {11},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {0305-1048},
  doi       = {10.1093/nar/gks196},
  pages     = {11},
  year      = {2012},
  abstract  = {The most crucial step in data processing from high-throughput sequencing applications is the accurate and sensitive alignment of the sequencing reads to reference genomes or transcriptomes. The accurate detection of insertions and deletions (indels) and errors introduced by the sequencing platform or by misreading of modified nucleotides is essential for the quantitative processing of the RNA-based sequencing (RNA-Seq) datasets and for the identification of genetic variations and modification patterns. We developed a new, fast and accurate algorithm for nucleic acid sequence analysis, FANSe, with adjustable mismatch allowance settings and ability to handle indels to accurately and quantitatively map millions of reads to small or large reference genomes. It is a seed-based algorithm which uses the whole read information for mapping and high sensitivity and low ambiguity are achieved by using short and non-overlapping reads. Furthermore, FANSe uses hotspot score to prioritize the processing of highly possible matches and implements modified Smith-Watermann refinement with reduced scoring matrix to accelerate the calculation without compromising its sensitivity. The FANSe algorithm stably processes datasets from various sequencing platforms, masked or unmasked and small or large genomes. It shows a remarkable coverage of low-abundance mRNAs which is important for quantitative processing of RNA-Seq datasets.},
  language  = {en}
}
@article{ZaccheusBroekerLundborgetal.2012,
  author    = {Zaccheus, Mona V. and Br{\"o}ker, Nina Kristin and Lundborg, Magnus and Uetrecht, Charlotte and Barbirz, Stefanie and Widmalm, Goran},
  title     = {Structural studies of the O-antigen polysaccharide from Escherichia coli TD2158 having O18 serogroup specificity and aspects of its interaction with the tailspike endoglycosidase of the infecting bacteriophage HK620},
  series = {Carbohydrate research},
  volume    = {357},
  journal   = {Carbohydrate research},
  number    = {8},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0008-6215},
  doi       = {10.1016/j.carres.2012.05.022},
  pages     = {118 -- 125},
  year      = {2012},
  abstract  = {We have analyzed the O-antigen polysaccharide of the previously uncharacterized Escherichia coli strain TD2158 which is a host of bacteriophage HK620. This bacteriophage recognizes and cleaves the polysaccharide with its tailspike protein (TSP). The polysaccharide preparation as well as oligosaccharides obtained from HK620TSP endoglycosidase digests were analyzed with NMR spectroscopy. Additionally, sugar analysis was performed on the O-antigen polysaccharide and MALDI-TOF MS was used in oligosaccharide analysis. The present study revealed a heterogeneous polysaccharide with a hexasaccharide repeating unit of the following structure: alpha-D-Glcp-(1 -> 6) vertical bar vertical bar 2)-alpha-L-Rhap-(1 -> 6)-alpha-D-Glcp-(1 -> 4)-alpha-D-Galp-(1 -> 3)-alpha-D-GlcpNAc- (1 ->vertical bar beta-D-Glcp/beta-D-GlcpNAc-(1 -> 3) A repeating unit with a D-GlcNAc substitution of D-Gal has been described earlier as characteristic for serogroup O18A1. Accordingly, we termed repeating units with D-Glc substitution at D-Gal as O18A2. NMR analyses of the polysaccharide confirmed that O18A1- and O18A2-type repeats were present in a 1:1 ratio. However, HK620TSP preferentially bound the D-GlcNAc- substituted O18A1-type repeating units in its high affinity binding pocket with a dissociation constant of 140 mu M and disfavored the O18A2-type having a beta-D-Glcp-(1 -> 3)-linked group. As a result, in hexasaccharide preparations, O18A1 and O18A2 repeats were present in a 9: 1 ratio stressing the clear preference of O18A1- type repeats to be cleaved by HK620TSP.},
  language  = {en}
}
@article{YarmanGroebeNeumannetal.2012,
  author    = {Yarman, Aysu and Gr{\"o}be, Glenn and Neumann, Bettina and Kinne, Mathias and Gajovic-Eichelmann, Nenad and Wollenberger, Ursula and Hofrichter, Martin and Ullrich, Rene and Scheibner, Katrin and Scheller, Frieder W.},
  title     = {The aromatic peroxygenase from Marasmius rutola-a new enzyme for biosensor applications},
  series = {Analytical \& bioanalytical chemistry},
  volume    = {402},
  journal   = {Analytical \& bioanalytical chemistry},
  number    = {1},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1618-2642},
  doi       = {10.1007/s00216-011-5497-y},
  pages     = {405 -- 412},
  year      = {2012},
  abstract  = {The aromatic peroxygenase (APO; EC 1.11.2.1) from the agraric basidomycete Marasmius rotula (MroAPO) immobilized at the chitosan-capped gold-nanoparticle-modified glassy carbon electrode displayed a pair of redox peaks with a midpoint potential of -278.5 mV vs. AgCl/AgCl (1 M KCl) for the Fe(2+)/Fe(3+) redox couple of the heme-thiolate-containing protein. MroAPO oxidizes aromatic substrates such as aniline, p-aminophenol, hydroquinone, resorcinol, catechol, and paracetamol by means of hydrogen peroxide. The substrate spectrum overlaps with those of cytochrome P450s and plant peroxidases which are relevant in environmental analysis and drug monitoring. In M. rotula peroxygenase-based enzyme electrodes, the signal is generated by the reduction of electrode-active reaction products (e.g., p-benzoquinone and p-quinoneimine) with electro-enzymatic recycling of the analyte. In these enzyme electrodes, the signal reflects the conversion of all substrates thus representing an overall parameter in complex media. The performance of these sensors and their further development are discussed.},
  language  = {en}
}
@phdthesis{Yarman2012,
  author    = {Yarman, Aysu},
  title     = {Biomimetic sensors for substrates of peroxidases and cytochrome P450s},
  address   = {Potsdam},
  pages     = {121 S.},
  year      = {2012},
  language  = {en}
}
@article{WurzbacherSalkaGrossart2012,
  author    = {Wurzbacher, Christian and Salka, Ivette and Grossart, Hans-Peter},
  title     = {Environmental actinorhodopsin expression revealed by a new in situ filtration and fixation sampler},
  series = {Environmental microbiology reports},
  volume    = {4},
  journal   = {Environmental microbiology reports},
  number    = {5},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1758-2229},
  doi       = {10.1111/j.1758-2229.2012.00350.x},
  pages     = {491 -- 497},
  year      = {2012},
  abstract  = {Freshwater Actinobacteria are an important and dominant group of bacterioplankton in most temperate freshwater systems. Recently, metagenomic studies discovered rhodopsin-like protein-coding sequences present in Actinobacteria which could be a decisive hint for their success in freshwater ecosystems. We analysed the diversity of actinorhodopsin (ActR) in Lake Stechlin (northern Germany) and assessed the actR expression profile during a diurnal cycle. We obtained 85 positive actR clones which could be subsequently grouped to 17 operational taxonomic units assuming a 90\% sequence similarity. The phylogenetic analysis points to a close relationship of all obtained sequences to the acI lineage of Actinobacteria, forming six independent clusters. For the first time, we followed in situ transcription of actR in Lake Stechlin revealing a rather constitutive circadian gene expression. For analysing in situ expression patterns of functional genes in aquatic ecosystems, such as actR, we invented a new in situ filtration and fixation sampler (IFFS). The IFFS enables the representative investigation of microbial transcriptomes in any aquatic ecosystem at all water depths. The IFFS sampler is simple and inexpensive, and we provide all engineering plans for an easy rebuild. Consequently, our IFFS is suitable to reliably study expression of any known functional gene of any aquatic microorganism.},
  language  = {en}
}
@phdthesis{Wurzbacher2012,
  author    = {Wurzbacher, Christian},
  title     = {Ecological function and biodiversity of aquatic fungi in lentic freshwater systems},
  address   = {Potsdam},
  pages     = {131 S.},
  year      = {2012},
  language  = {en}
}
@phdthesis{Wu2012,
  author    = {Wu, Xu-Na},
  title     = {Functional characterization of AtSP1, a nutrient-induced receptor-like kinase},
  address   = {Potsdam},
  pages     = {112 S.},
  year      = {2012},
  language  = {en}
}
@article{WuAlluGarapatietal.2012,
  author    = {Wu, Anhui and Allu, Annapurna Devi and Garapati, Prashanth and Siddiqui, Hamad and Dortay, Hakan and Zanor, Maria-Ines and Asensi-Fabado, Maria Amparo and Munne-Bosch, Sergi and Antonio, Carla and Tohge, Takayuki and Fernie, Alisdair R. and Kaufmann, Kerstin and Xue, Gang-Ping and M{\"u}ller-R{\"o}ber, Bernd and Balazadeh, Salma},
  title     = {Jungbrunnen1, a reactive oxygen species-responsive NAC transcription factor, regulates longevity in arabidopsis},
  series = {The plant cell},
  volume    = {24},
  journal   = {The plant cell},
  number    = {2},
  publisher = {American Society of Plant Physiologists},
  address   = {Rockville},
  issn      = {1040-4651},
  doi       = {10.1105/tpc.111.090894},
  pages     = {482 -- 506},
  year      = {2012},
  abstract  = {The transition from juvenility through maturation to senescence is a complex process that involves the regulation of longevity. Here, we identify JUNGBRUNNEN1 (JUB1), a hydrogen peroxide (H2O2)-induced NAC transcription factor, as a central longevity regulator in Arabidopsis thaliana. JUB1 overexpression strongly delays senescence, dampens intracellular H2O2 levels, and enhances tolerance to various abiotic stresses, whereas in jub1-1 knockdown plants, precocious senescence and lowered abiotic stress tolerance are observed. A JUB1 binding site containing a RRYGCCGT core sequence is present in the promoter of DREB2A, which plays an important role in abiotic stress responses. JUB1 transactivates DREB2A expression in mesophyll cell protoplasts and transgenic plants and binds directly to the DREB2A promoter. Transcriptome profiling of JUB1 overexpressors revealed elevated expression of several reactive oxygen species-responsive genes, including heat shock protein and glutathione S-transferase genes, whose expression is further induced by H2O2 treatment. Metabolite profiling identified elevated Pro and trehalose levels in JUB1 overexpressors, in accordance with their enhanced abiotic stress tolerance. We suggest that JUB1 constitutes a central regulator of a finely tuned control system that modulates cellular H2O2 level and primes the plants for upcoming stress through a gene regulatory network that involves DREB2A.},
  language  = {en}
}
@article{WinckRianoPachonSommeretal.2012,
  author    = {Winck, Flavia V. and Riano-Pachon, Diego M. and Sommer, Frederik and Rupprecht, Jens and M{\"u}ller-R{\"o}ber, Bernd},
  title     = {The nuclear proteome of the green alga Chlamydomonas reinhardtii},
  series = {Proteomics},
  volume    = {12},
  journal   = {Proteomics},
  number    = {1},
  publisher = {Wiley-Blackwell},
  address   = {Malden},
  issn      = {1615-9853},
  doi       = {10.1002/pmic.201000782},
  pages     = {95 -- 100},
  year      = {2012},
  abstract  = {Nuclear proteins play a central role in regulating gene expression. Their identification is important for understanding how the nuclear repertoire changes over time under different conditions. Nuclear proteins are often underrepresented in proteomic studies due to the frequently low abundance of proteins involved in regulatory processes. So far, only few studies describing the nuclear proteome of plant species have been published. Recently, the genome sequence of the unicellular green alga Chlamydomonas reinhardtii has been obtained and annotated, allowing the development of further detailed studies for this organism. However, a detailed description of its nuclear proteome has not been reported so far. Here, we present an analysis of the nuclear proteome of the sequenced Chlamydomonas strain cc503. Using LC-MS/MS, we identified 672 proteins from nuclei isolates with a maximum 1\% peptide spectrum false discovery rate. Besides well-known proteins (e.g. histones), transcription factors and other transcriptional regulators (e.g. tubby and HMG) were identified. The presence of protein motifs in nuclear proteins was investigated by computational tools, and specific over-represented protein motifs were identified. This study provides new insights into the complexity of the nuclear environment and reveals novel putative protein targets for further studies of nuclear mechanisms.},
  language  = {en}
}
@article{WildishPavesiKetmaier2012,
  author    = {Wildish, J. and Pavesi, Laura and Ketmaier, Valerio},
  title     = {Talitrid amphipods (Crustacea: Amphipoda: Talitridae) and the driftwood ecological niche a morphological and molecular study},
  series = {Journal of natural history : an international journal of systematics, interactive biology and biodiversity. - London : Taylor \& Francis   1.1967 -},
  volume    = {46},
  journal   = {Journal of natural history : an international journal of systematics, interactive biology and biodiversity. - London : Taylor \& Francis   1.1967 -},
  number    = {43-44},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {Abingdon},
  issn      = {0022-2933},
  doi       = {10.1080/00222933.2012.717971},
  pages     = {2677 -- 2700},
  year      = {2012},
  abstract  = {Coastal regions of the North East Atlantic and Mediterranean Seas have four known species of driftwood talitrids. Records are extremely scanty, often limited to the type locality and dating to 1950. We were able to study three of them, all belonging to the genus Macarorchestia, using fresh and archived samples including type material. Allometric and molecular analyses support: (1) a close relationship among all the three classically defined Macarorchestia species, (2) Macarorchestia was well separated from non-driftwood taxa, and (3) a putative new driftwood talitrid discovered during this study was not closely related to Macarorchestia. Genetic divergence between the new species and Macarorchestia remyi is as high as the average distance among a number of talitrid species included in the study for comparison. A key is provided to identify all three of the presently known species of Macarorchestia, using morphological characters employed in the allometric study.},
  language  = {en}
}
@phdthesis{Wiegand2012,
  author    = {Wiegand, Kathlen},
  title     = {Untersuchung der Auswirkung von Trockenstress auf verschiedene K{\"u}rbisgew{\"a}chse unter spezieller Betrachtung des Phloems},
  address   = {Potsdam},
  pages     = {102 S.},
  year      = {2012},
  language  = {de}
}
@article{WernetKunnusSchrecketal.2012,
  author    = {Wernet, Philippe and Kunnus, Kristjan and Schreck, Simon and Quevedo, Wilson and Kurian, Reshmi and Techert, Simone and de Groot, Frank M. F. and Odelius, Michael and F{\"o}hlisch, Alexander},
  title     = {Dissecting local atomic and intermolecular interactions of transition-metal ions in solution with selective X-ray spectroscopy},
  series = {The journal of physical chemistry letters},
  volume    = {3},
  journal   = {The journal of physical chemistry letters},
  number    = {23},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1948-7185},
  doi       = {10.1021/jz301486u},
  pages     = {3448 -- 3453},
  year      = {2012},
  abstract  = {Determining covalent and charge-transfer contributions to bonding in solution has remained an experimental challenge. Here, the quenching of fluorescence decay channels as expressed in dips in the L-edge X-ray spectra of solvated 3d transition-metal ions and complexes was reported as a probe. With a full set of experimental and theoretical ab initio L-edge X-ray spectra of aqueous Cr3+, including resonant inelastic X-ray scattering, we address covalency and charge transfer for this prototypical transition-metal ion in solution. We dissect local atomic effects from intermolecular interactions and quantify X-ray optical effects. We find no evidence for the asserted ultrafast charge transfer to the solvent and show that the dips are readily explained by X-ray optical effects and local atomic state dependence of the fluorescence yield. Instead, we find, besides ionic interactions, a covalent contribution to the bonding in the aqueous complex of ligand-to-metal charge-transfer character.},
  language  = {en}
}
@article{WellsO'HaraBoehmetal.2012,
  author    = {Wells, Konstans and O'Hara, R. B. and Boehm, S. M. and Gockel, Sonja and Hemp, Andreas and Renner, S. C. and Pfeiffer, S. and Boehning-Gaese, Katrin and Kalko, Elisabeth K. V.},
  title     = {Trait-dependent occupancy dynamics of birds in temperate forest landscapes fine-scale observations in a hierarchical multi-species framework},
  series = {Animal conservation},
  volume    = {15},
  journal   = {Animal conservation},
  number    = {6},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1367-9430},
  doi       = {10.1111/j.1469-1795.2012.00560.x},
  pages     = {626 -- 637},
  year      = {2012},
  abstract  = {Silvicultural practices lead to changes in forest composition and structure and may impact species diversity from the overall regional species pool to stand-level species occurrence. We explored to what extent fine-scale occupancy patterns in differently managed forest stands are driven by environment and ecological traits in three regions in Germany using a multi-species hierarchical model. We tested for the possible impact of environmental variables and ecological traits on occupancy dynamics in a joint modelling exercise while taking possible variation in coefficient estimates over years and plots into account. Bird species richness differed across regions and years, and trends in species richness across years were different in the three regions. On the species level, forest management affected occupancy of species in all regions, but only 35\% of the total assemblage-level variation in occurrence probability was explained by either forest type and successional stage and <?1\% by forest edge. On the assemblage level, bird occurrence decreased with body mass in all regions. Species with smaller breeding ranges had lower occurrence probabilities in one region, while later spring arrival decreased occurrence probabilities in the two other regions. Spatial variation in the effect size of trait covariates such as species phylogeny and breeding strata showed that variation in patch occupancy due to fine-scale differences in forest management is, to some extent, predictable from ecological traits. Our results show that environmental factors and ecological traits jointly predict variation in bird occupancy patterns and their response to forest management. Observations at the fine scale of forest stands, at which conservation efforts can be arranged along with forest management practices in heterogeneous environments, have been shown to provide meaningful insights despite the difficulties involved in monitoring mobile organisms such as birds at the plot level.},
  language  = {en}
}
@misc{WelkerDittmannThuenemannvonDoehren2012,
  author    = {Welker, Martin and Dittmann-Th{\"u}nemann, Elke and von Doehren, Hans},
  title     = {Cyanobacteria as a source of natural products},
  series = {Methods in enzymology},
  volume    = {517},
  journal   = {Methods in enzymology},
  number    = {1},
  editor    = {Hopwood, DA},
  publisher = {Elsevier},
  address   = {San Diego},
  isbn      = {978-0-12-404634-4},
  issn      = {0076-6879},
  doi       = {10.1016/B978-0-12-404634-4.00002-4},
  pages     = {23 -- 46},
  year      = {2012},
  abstract  = {Cyanobacteria or blue-green algae from various environments have been recognized as sources of a variety of bioactive metabolites. Strategies of strain isolation from aquatic habitats, and cultivation and harvesting for metabolite production are described. Strategies for screening of compounds are discussed, including their direct MALDI-TOF mass spectrometric detection in whole cells. Genetic approaches including genomic mining, mutagenesis including transcriptional activation, heterologous expression, and in vitro. reconstitution of pathways are presented.},
  language  = {en}
}
@phdthesis{Wehle2012,
  author    = {Wehle, Marko},
  title     = {Entwicklung und Untersuchung eines Atomatischen Modells des Glykoseylphosphatidylinostol-Ankers},
  address   = {Potsdam},
  pages     = {101 S.},
  year      = {2012},
  language  = {de}
}
@unpublished{WannickeEndresEngeletal.2012,
  author    = {Wannicke, Nicola and Endres, S. and Engel, A. and Grossart, Hans-Peter and Nausch, M. and Unger, J. and Voss, Martin},
  title     = {Response of nodularia spumigena to pCO(2) - Part 1: Growth, production and nitrogen cycling},
  series = {Biogeosciences},
  volume    = {9},
  journal   = {Biogeosciences},
  number    = {8},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1726-4170},
  doi       = {10.5194/bg-9-2973-2012},
  pages     = {2973 -- 2988},
  year      = {2012},
  abstract  = {Heterocystous cyanobacteria of the genus Nodularia form extensive blooms in the Baltic Sea and contribute substantially to the total annual primary production. Moreover, they dispense a large fraction of new nitrogen to the ecosystem when inorganic nitrogen concentration in summer is low. Thus, it is of ecological importance to know how Nodularia will react to future environmental changes, in particular to increasing carbon dioxide (CO2) concentrations and what consequences there might arise for cycling of organic matter in the Baltic Sea. Here, we determined carbon (C) and dinitrogen (N-2) fixation rates, growth, elemental stoichiometry of particulate organic matter and nitrogen turnover in batch cultures of the heterocystous cyanobacterium Nodularia spumigena under low (median 315 mu atm), mid (median 353 mu atm), and high (median 548 mu atm) CO2 concentrations. Our results demonstrate an overall stimulating effect of rising pCO(2) on C and N-2 fixation, as well as on cell growth. An increase in pCO(2) during incubation days 0 to 9 resulted in an elevation in growth rate by 84 +/- 38\% (low vs. high pCO(2)) and 40 +/- 25\% (mid vs. high pCO(2)), as well as in N-2 fixation by 93 +/- 35\% and 38 +/- 1\%, respectively. C uptake rates showed high standard deviations within treatments and in between sampling days. Nevertheless, C fixation in the high pCO(2) treatment was elevated compared to the other two treatments by 97\% (high vs. low) and 44\% (high vs. mid) at day 0 and day 3, but this effect diminished afterwards. Additionally, elevation in carbon to nitrogen and nitrogen to phosphorus ratios of the particulate biomass formed (POC : POP and PON : POP) was observed at high pCO(2). Our findings suggest that rising pCO(2) stimulates the growth of heterocystous diazotrophic cyanobacteria, in a similar way as reported for the non-heterocystous diazotroph Trichodesmium. Implications for biogeochemical cycling and food web dynamics, as well as ecological and socio-economical aspects in the Baltic Sea are discussed.},
  language  = {en}
}
@article{WangKoehlerCaoetal.2012,
  author    = {Wang, Wei-Hong and K{\"o}hler, Barbara and Cao, Feng-Qiu and Liu, Guo-Wei and Gong, Yuan-Yong and Sheng, Song and Song, Qi-Chao and Cheng, Xiao-Yuan and Garnett, Trevor and Okamoto, Mamoru and Qin, Rui and M{\"u}ller-R{\"o}ber, Bernd and Tester, Mark and Liu, Lai-Hua},
  title     = {Rice DUR3 mediates high-affinity urea transport and plays an effective role in improvement of urea acquisition and utilization when expressed in Arabidopsis},
  series = {New phytologist : international journal of plant science},
  volume    = {193},
  journal   = {New phytologist : international journal of plant science},
  number    = {2},
  publisher = {Wiley-Blackwell},
  address   = {Malden},
  issn      = {0028-646X},
  doi       = {10.1111/j.1469-8137.2011.03929.x},
  pages     = {432 -- 444},
  year      = {2012},
  abstract  = {Despite the great agricultural and ecological importance of efficient use of urea-containing nitrogen fertilizers by crops, molecular and physiological identities of urea transport in higher plants have been investigated only in Arabidopsis. We performed short-time urea-influx assays which have identified a low-affinity and high-affinity (Km of 7.55 mu M) transport system for urea-uptake by rice roots (Oryza sativa). A high-affinity urea transporter OsDUR3 from rice was functionally characterized here for the first time among crops. OsDUR3 encodes an integral membrane-protein with 721 amino acid residues and 15 predicted transmembrane domains. Heterologous expression demonstrated that OsDUR3 restored yeast dur3-mutant growth on urea and facilitated urea import with a Km of c. 10 mu M in Xenopus oocytes. Quantitative reverse-transcription polymerase chain reaction (qPCR) analysis revealed upregulation of OsDUR3 in rice roots under nitrogen-deficiency and urea-resupply after nitrogen-starvation. Importantly, overexpression of OsDUR3 complemented the Arabidopsis atdur3-1 mutant, improving growth on low urea and increasing root urea-uptake markedly. Together with its plasma membrane localization detected by green fluorescent protein (GFP)-tagging and with findings that disruption of OsDUR3 by T-DNA reduces rice growth on urea and urea uptake, we suggest that OsDUR3 is an active urea transporter that plays a significant role in effective urea acquisition and utilisation in rice.},
  language  = {en}
}
@phdthesis{Walther2012,
  author    = {Walther, Dirk},
  title     = {Bioinformatics studies of biological systems across multiple levels of molecular organization},
  address   = {Potsdam},
  pages     = {124 S.},
  year      = {2012},
  language  = {en}
}
@article{WackerMartinCreuzburg2012,
  author    = {Wacker, Alexander and Martin-Creuzburg, Dominik},
  title     = {Biochemical nutrient requirements of the rotifer Brachionus calyciflorus co-limitation by sterols and amino acids},
  series = {Functional ecology : an official journal of the British Ecological Society},
  volume    = {26},
  journal   = {Functional ecology : an official journal of the British Ecological Society},
  number    = {5},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0269-8463},
  doi       = {10.1111/j.1365-2435.2012.02047.x},
  pages     = {1135 -- 1143},
  year      = {2012},
  abstract  = {It has been proposed that growth and reproduction of animals is frequently limited by multiple nutrients simultaneously. To improve our understanding of the consequences of multiple nutrient limitations (i.e. co-limitation) for the performance of animals, we conducted standardized population growth experiments using an important aquatic consumer, the rotifer Brachionus calyciflorus. We compared nutrient profiles (sterols, fatty acids and amino acids) of rotifers and their diets to reveal consumerdiet imbalances and thus potentially limiting nutrients. In concomitant growth experiments, we directly supplemented potentially limiting substances (sterols, fatty acids, amino acids) to a nutrient-deficient diet, the cyanobacterium Synechococcus elongatus, and recorded population growth rates. The results from the supplementation experiments corroborated the nutrient limitations predicted by assessing consumerdiet imbalances, but provided more detailed information on co-limiting nutrients. While the fatty acid deficiency of the cyanobacterium appeared to be of minor importance, the addition of both cholesterol and certain amino acids (leucine and isoleucine) improved population growth rates of rotifers, indicating a simultaneous limitation by sterols and amino acids. Our results add to growing evidence that consumers frequently face multiple nutrient limitations and suggest that the concept of co-limitation has to be considered in studies assessing nutrient-limited growth responses of consumers.},
  language  = {en}
}
@article{VerheyenBaetenDeFrenneetal.2012,
  author    = {Verheyen, Kris and Baeten, Lander and De Frenne, Pieter and Bernhardt-R{\"o}mermann, Markus and Brunet, Jorg and Cornelis, Johnny and Decocq, Guillaume and Dierschke, Hartmut and Eriksson, Ove and Hedl, Radim and Heinken, Thilo and Hermy, Martin and Hommel, Patrick and Kirby, Keith J. and Naaf, Tobias and Peterken, George and Petrik, Petr and Pfadenhauer, Joerg and Van Calster, Hans and Walther, Gian-Reto and Wulf, Monika and Verstraeten, Gorik},
  title     = {Driving factors behind the eutrophication signal in understorey plant communities of deciduous temperate forests},
  series = {The journal of ecology},
  volume    = {100},
  journal   = {The journal of ecology},
  number    = {2},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0022-0477},
  doi       = {10.1111/j.1365-2745.2011.01928.x},
  pages     = {352 -- 365},
  year      = {2012},
  abstract  = {1. Atmospheric nitrogen (N) deposition is expected to change forest understorey plant community composition and diversity, but results of experimental addition studies and observational studies are not yet conclusive. A shortcoming of observational studies, which are generally based on resurveys or sampling along large deposition gradients, is the occurrence of temporal or spatial confounding factors. 2. We were able to assess the contribution of N deposition versus other ecological drivers on forest understorey plant communities by combining a temporal and spatial approach. Data from 1205 (semi-)permanent vegetation plots taken from 23 rigorously selected understorey resurvey studies along a large deposition gradient across deciduous temperate forest in Europe were compiled and related to various local and regional driving factors, including the rate of atmospheric N deposition, the change in large herbivore densities and the change in canopy cover and composition. 3. Although no directional change in species richness occurred, there was considerable floristic turnover in the understorey plant community and a shift in species composition towards more shade-tolerant and nutrient-demanding species. However, atmospheric N deposition was not important in explaining the observed eutrophication signal. This signal seemed mainly related to a shift towards a denser canopy cover and a changed canopy species composition with a higher share of species with more easily decomposed litter. 4. Synthesis. Our multi-site approach clearly demonstrates that one should be cautious when drawing conclusions about the impact of atmospheric N deposition based on the interpretation of plant community shifts in single sites or regions due to other, concurrent, ecological changes. Even though the effects of chronically increased N deposition on the forest plant communities are apparently obscured by the effects of canopy changes, the accumulated N might still have a significant impact. However, more research is needed to assess whether this N time bomb will indeed explode when canopies will open up again.},
  language  = {en}
}
@article{VerganiCarminatiFerrarietal.2012,
  author    = {Vergani, Marco and Carminati, Marco and Ferrari, Giorgio and Landini, Ettore and Caviglia, Claudia and Heiskanen, Arto and Comminges, Clement and Zor, Kinga and Sabourin, David and Dufva, Martin and Dimaki, Maria and Raiteri, Roberto and Wollenberger, Ursula and Emneus, Jenny and Sampietro, Marco},
  title     = {Multichannel bipotentiostat integrated with a microfluidic platform for electrochemical real-time monitoring of cell cultures},
  series = {IEEE Transactions on biomedical circuits and systems},
  volume    = {6},
  journal   = {IEEE Transactions on biomedical circuits and systems},
  number    = {5},
  publisher = {Inst. of Electr. and Electronics Engineers},
  address   = {Piscataway},
  issn      = {1932-4545},
  doi       = {10.1109/TBCAS.2012.2187783},
  pages     = {498 -- 507},
  year      = {2012},
  abstract  = {An electrochemical detection system specifically designed for multi-parameter real-time monitoring of stem cell culturing/differentiation in a microfluidic system is presented. It is composed of a very compact 24-channel electronic board, compatible with arrays of microelectrodes and coupled to a microfluidic cell culture system. A versatile data acquisition software enables performing amperometry, cyclic voltammetry and impedance spectroscopy in each of the 12 independent chambers over a 100 kHz bandwidth with current resolution down to 5 pA for 100 ms measuring time. The design of the platform, its realization and experimental characterization are reported, with emphasis on the analysis of impact of input capacitance (i.e., microelectrode size) and microfluidic pump operation on current noise. Programmable sequences of successive injections of analytes (ferricyanide and dopamine) and rinsing buffer solution as well as the impedimetric continuous tracking for seven days of the proliferation of a colony of PC12 cells are successfully demonstrated.},
  language  = {en}
}
@phdthesis{Vasilevski2012,
  author    = {Vasilevski, Aleksandar},
  title     = {Research in pectin synthesis by analysing the seed coat mucilage},
  address   = {Potsdam},
  pages     = {134 S.},
  year      = {2012},
  language  = {en}
}
@article{VarshneyKumarIgnatovaetal.2012,
  author    = {Varshney, Nishant Kumar and Kumar, R. Suresh and Ignatova, Zoya and Prabhune, Asmita and Pundle, Archana and Dodson, Eleanor and Suresh, C. G.},
  title     = {Crystallization and X-ray structure analysis of a thermostable penicillin G acylase from Alcaligenes faecalis},
  series = {Acta crystallographica : Section F, Structural biology communications},
  volume    = {68},
  journal   = {Acta crystallographica : Section F, Structural biology communications},
  number    = {3},
  publisher = {Wiley-Blackwell},
  address   = {Malden},
  issn      = {1744-3091},
  doi       = {10.1107/S1744309111053930},
  pages     = {273 -- 277},
  year      = {2012},
  abstract  = {The enzyme penicillin G acylase (EC 3.5.1.11) catalyzes amide-bond cleavage in benzylpenicillin (penicillin G) to yield 6-aminopenicillanic acid, an intermediate chemical used in the production of semisynthetic penicillins. A thermostable penicillin G acylase from Alcaligenes faecalis (AfPGA) has been crystallized using the hanging-drop vapour-diffusion method in two different space groups: C2221, with unit-cell parameters a = 72.9, b = 86.0, c = 260.2 angstrom, and P41212, with unit-cell parameters a = b = 85.6, c = 298.8 angstrom. Data were collected at 293 K and the structure was determined using the molecular-replacement method. Like other penicillin acylases, AfPGA belongs to the N-terminal nucleophilic hydrolase superfamily, has undergone post-translational processing and has a serine as the N-terminal residue of the beta-chain. A disulfide bridge has been identified in the structure that was not found in the other two known penicillin G acylase structures. The presence of the disulfide bridge is perceived to be one factor that confers higher stability to this enzyme.},
  language  = {en}
}
@phdthesis{Uttamchand2012,
  author    = {Uttamchand, Narendra Kumar},
  title     = {Shape-memory properties of magnetically active compositives based on multiphase polymer networks},
  address   = {Potsdam},
  pages     = {XI, 113 S.},
  year      = {2012},
  language  = {en}
}
@article{UllnerAresMorellietal.2012,
  author    = {Ullner, E. and Ares, S. and Morelli, L. G. and Oates, A. C. and J{\"u}licher, F. and Nicola, E. and Heussen, R. and Whitmore, D. and Blyuss, K. and Fryett, M. and Zakharova, A. and Koseska, A. and Nene, N. R. and Zaikin, Alexei},
  title     = {Noise and oscillations in biological sysems multidisciplinary approach between experimental biology, theoretical modelling and synthetic biology},
  series = {International journal of modern physics : B, Condensed matter physics, statistical physics, applied physics},
  volume    = {26},
  journal   = {International journal of modern physics : B, Condensed matter physics, statistical physics, applied physics},
  number    = {25},
  publisher = {World Scientific},
  address   = {Singapore},
  issn      = {0217-9792},
  doi       = {10.1142/S0217979212460095},
  pages     = {12},
  year      = {2012},
  abstract  = {Rapid progress of experimental biology has provided a huge flow of quantitative data, which can be analyzed and understood only through the application of advanced techniques recently developed in theoretical sciences. On the other hand, synthetic biology enabled us to engineer biological models with reduced complexity. In this review we discuss that a multidisciplinary approach between this sciences can lead to deeper understanding of the underlying mechanisms behind complex processes in biology. Following the mini symposia "Noise and oscillations in biological systems" on Physcon 2011 we have collected different research examples from theoretical modeling, experimental and synthetic biology.},
  language  = {en}
}
@article{UhligMadaboosiSchmidtetal.2012,
  author    = {Uhlig, Katja and Madaboosi, Narayanan and Schmidt, Stephan and J{\"a}ger, Magnus S. and Rose, J{\"u}rgen and Duschl, Claus and Volodkin, Dmitry V.},
  title     = {3d localization and diffusion of proteins in polyelectrolyte multilayers},
  series = {Soft matter},
  volume    = {8},
  journal   = {Soft matter},
  number    = {47},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1744-683X},
  doi       = {10.1039/c2sm26500a},
  pages     = {11786 -- 11789},
  year      = {2012},
  abstract  = {The interaction of diverse biomaterials with surfaces is more crucial than ever for biomedical applications to ensure efficiency and reproducibility. Very interesting surface materials are micrometer-thick polyelectrolyte multilayers. Not only their surface but also the bulk can be loaded with biomaterials like proteins or DNA for various purposes. Therefore, we established a method to analyze the lateral and vertical distribution of fluorescently labelled proteins of various size and charge in polyelectrolyte films composed of poly(L-lysine) and hyaluronic acid by confocal laser scanning microscopy. This approach enables us to measure the diffusion coefficients of the proteins via fluorescence recovery after photobleaching as a function of their vertical position in the film and facilitates the understanding of molecular interactions in the film with a high resolution in both space and time. As a result, we confirm that protein loading in the film is driven by electrostatic interactions - uncharged dextran molecules of 10 and 500 kDa do not diffuse into the film. Proteins of different sizes (3-11 nm) can diffuse relatively fast (D = 2-4 mm(2) s(-1)) independent of their net charge, indicating complex interpolymer interactions. This approach is a new powerful experimental tool to design the polyelectrolyte multilayers for bio-applications by finding a relationship between intermolecular interactions and mobility and availability of biomolecules to biological samples (e.g. cells) or detection units (e.g. biosensors).},
  language  = {en}
}
@article{TuerkeAndreasGossneretal.2012,
  author    = {T{\"u}rke, Manfred and Andreas, Kerstin and Gossner, Martin M. and Kowalski, Esther and Lange, Markus and Boch, Steffen and Socher, Stephanie A. and M{\"u}ller, J{\"o}rg and Prati, Daniel and Fischer, Markus and Meyh{\"o}fer, Rainer and Weisser, Wolfgang W.},
  title     = {Are gastropods, rather than ants, important dispersers of seeds of myrmecochorous forest herbs?},
  series = {The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences},
  volume    = {179},
  journal   = {The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences},
  number    = {1},
  publisher = {Univ. of Chicago Press},
  address   = {Chicago},
  issn      = {0003-0147},
  doi       = {10.1086/663195},
  pages     = {124 -- 131},
  year      = {2012},
  abstract  = {Seed dispersal by ants (myrmecochory) is widespread, and seed adaptations to myrmecochory are common, especially in the form of fatty appendices (elaiosomes). In a recent study, slugs were identified as seed dispersers of myrmecochores in a central European beech forest. Here we used 105 beech forest sites to test whether myrmecochore presence and abundance is related to ant or gastropod abundance and whether experimentally exposed seeds are removed by gastropods. Myrmecochorous plant cover was positively related to gastropod abundance but was negatively related to ant abundance. Gastropods were responsible for most seed removal and elaiosome damage, whereas insects (and rodents) played minor roles. These gastropod effects on seeds were independent of region or forest management. We suggest that terrestrial gastropods can generally act as seed dispersers of myrmecochorous plants and even substitute myrmecochory, especially where ants are absent or uncommon.},
  language  = {en}
}
@phdthesis{Trescher2012,
  author    = {Trescher, Karoline},
  title     = {Cokulturtestsystem f{\"u}r die Untersuchung des Einflusses physikochemischer Eigenschaften von Copolymeren auf das Verhalten von Keratinozyten und Fibroblasten},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-62915},
  school      = {Universit{\"a}t Potsdam},
  year      = {2012},
  abstract  = {Chemische und physikalische Eigenschaften von Polymeren k{\"o}nnen verschiedene Zelltypen unterschiedlich, z. B. hinsichtlich Adh{\"a}renz oder Funktionalit{\"a}t, beeinflussen. Die Elastizit{\"a}t eines Polymers beeinflusst vor allem, welche Zugkr{\"a}fte eine Zelle gegen{\"u}ber ihrem Substrat entwickeln kann. Das Zellverhalten wird dann {\"u}ber intrazellul{\"a}re R{\"u}ckkopplungsmechanismen reguliert. Die Oberfl{\"a}chenladung und/oder Hydrophilie eines Polymers beeinflusst zun{\"a}chst die Adsorption von Ionen, Proteinen und anderen Molek{\"u}len. Vor allem {\"u}ber die Zusammensetzung, Dichte und Konformation der adsorbierten Komponenten werden anschließend die Wechselwirkungen mit den Zellen vermittelt. Des Weiteren k{\"o}nnen verschiedene Zelltypen unterschiedliche membranassoziierte Proteine, Zucker und Lipide aufweisen, so dass Polymereigenschaften zellspezifische Effekte bewirken k{\"o}nnen. F{\"u}r biotechnologische Anwendungen und f{\"u}r den Einsatz in der regenerativen Medizin gewinnen Polymere, die spezifische Zellreaktionen regulieren k{\"o}nnen, immer weiter an Bedeutung. Die Isolierung und Kultur von prim{\"a}ren Keratinozyten ist noch immer anspruchsvoll und die ad{\"a}quate Heilung von Hautwunden stellt eine fortw{\"a}hrende medizinische Herausforderung dar. Ein Polymer, das eine bevorzugte Adh{\"a}renz von Keratinozyten bei gleichzeitig verminderter Anheftung dermaler Fibroblasten erm{\"o}glicht, w{\"u}rde erhebliche Vorteile f{\"u}r den Einsatz in der Keratinozyten-Zellkultur und als Wundauflage bieten. Um den potentiell spezifischen Einfluss bestimmter Polymereigenschaften auf prim{\"a}re humane Keratinozyten und dermale Fibroblasten zu untersuchen, wurde in der vorliegenden Arbeit ein Zellkultursystem f{\"u}r die Mono- und Cokultur beider Zelltypen entwickelt. Das Testsystem wurde als Screening konzipiert, um den Einfluss unterschiedlicher Polymereigenschaften in mehreren Abstufungen auf die Zellen zu untersuchen. Folgende Parameter wurden untersucht: 1. Vitalit{\"a}t und Dichte adh{\"a}renter und nicht-adh{\"a}rierter Zellen, 2. Sch{\"a}digung der Zellmembran, 3. selektive Adh{\"a}renz von Keratinozyten in Cokultur durch die spezifische immunzytochemische F{\"a}rbung von Keratin14 und Vimentin. F{\"u}r die Polymere mit variabler Elastizit{\"a}t wurden zus{\"a}tzlich die Ablagerung extrazellul{\"a}rer Matrixkomponenten und die Sekretion l{\"o}slicher Faktoren durch die Zellen untersucht. Als Modellpolymere f{\"u}r die Variation der Elastizit{\"a}t wurden vernetzte Poly(n-butylacrylate) (cPnBA) verwendet, da deren Elastizit{\"a}t durch den Anteil des Vernetzers eingestellt werden kann. Auf dem weniger elastischen cPnBA zeigte sich in der Cokultur ein doppelt so hohes Verh{\"a}ltnis von Keratinozyten zu Fibroblasten wie auf dem elastischeren cPnBA, so dass ein leichter zellselektiver Effekt angenommen werden kann. Acrylnitril-basierte Copolymere wurden als Modellpolymere f{\"u}r die Variation der Oberfl{\"a}chenladung und Hydrophilie verwendet, da die Eigenschaften durch Art und molaren Anteil des Comonomers eingestellt werden k{\"o}nnen. Durch Variation des molaren Anteils der Comonomere mit positiver bzw. negativer Ladung, Methacryls{\"a}ure-2-aminoethylester-hydrochhlorid (AEMA) und N-3-Aminopropyl-methacrylamid-hydro-chlorid (APMA) bzw. Natriumsalz der 2-Methyl-2-propen-1-sulfons{\"a}ure (NaMAS), wurde der Anteil der positiven bzw. negativen Ladung im Copolymer variiert. Durch die Erh{\"o}hung des molaren Anteils des hydrophilen Comonomers N-Vinylpyrrolidon (NVP) wurde die Hydrophilie des Copolymers gesteigert. Die Erh{\"o}hung des molaren Anteils an positiv geladenem Comonomer AEMA im Copolymer f{\"u}hrte tendenziell zu einer h{\"o}heren Keratinozytendichte, wobei die Fibroblastendichte unver{\"a}ndert blieb. Durch die Erh{\"o}hung des molaren Anteils des positiv geladenen Comonomers APMA ergaben sich keine deutlichen Unterschiede in Dichte, Vitalit{\"a}t oder Selektivit{\"a}t der Zellen. Durch die stufenweise Erh{\"o}hung des molaren Anteils des negativ geladenen Comonomers NaMAS konnte, wie im Falle von AEMA, eine Tendenz zur verbesserten Keratinozytenadh{\"a}renz beobachtet werden. Die Steigerung der Hydrophilie der Copolymere f{\"u}hrte sowohl f{\"u}r Keratinozyten als auch f{\"u}r Fibroblasten zu einer reduzierten Adh{\"a}renz und Vitalit{\"a}t. In der vorliegenden Doktorarbeit wurde ein Testverfahren etabliert, das die Untersuchung von prim{\"a}ren humanen Keratinozyten und prim{\"a}ren humanen Fibroblasten in Monokultur und Cokultur auf verschiedenen Polymeren erm{\"o}glicht. Die bisherigen Ergebnisse zeigen, dass sich durch die gezielte Modifizierung verschiedener Polymereigenschaften die Adh{\"a}renz und Vitalit{\"a}t beider Zelltypen beeinflussen l{\"a}sst. Die Reduktion der Elastizit{\"a}t sowie die Erh{\"o}hung des molaren Anteils geladener Comonomere f{\"u}hrten zu einer Zunahme der Keratinozytenadh{\"a}renz. Da die Fibroblasten unbeeinflusst blieben, zeigte sich f{\"u}r einige der untersuchten Polymere eine leichte Zellselektivit{\"a}t. Diese k{\"o}nnte durch die weitere Erh{\"o}hung der Steifigkeit oder des Anteils geladener Comonomere m{\"o}glicherweise weiter gesteigert werden.},
  language  = {de}
}
@phdthesis{Tientcheu2012,
  author    = {Tientcheu, Charles Merlin},
  title     = {Entwicklung von neuartigen amperometrischen Affinit{\"a}tssensoren mit PQQ-abh{\"a}ngiger Glucosedehydrogenase als Markereenzym},
  address   = {Potsdam},
  pages     = {119 S.},
  year      = {2012},
  language  = {de}
}
@phdthesis{Thalhammer2012,
  author    = {Thalhammer, Anja},
  title     = {Physiological, functional and structural characterization of five closely related COR/LEA (COld Regulated/Late Embroygenesis Abundant) proteins from Arabidopsis thaliana (L.)},
  address   = {Potsdam},
  pages     = {137 S.},
  year      = {2012},
  language  = {en}
}
@article{TegetmeyerThomaArbeiter2012,
  author    = {Tegetmeyer, Cosima and Thoma, Marco and Arbeiter, Susanne},
  title     = {Moult and mobility of the Aquatic Warbler Acrocephalus paludicola on the West African non-breeding grounds},
  series = {Journal of ornithology},
  volume    = {153},
  journal   = {Journal of ornithology},
  number    = {4},
  publisher = {Springer},
  address   = {New York},
  issn      = {0021-8375},
  doi       = {10.1007/s10336-012-0833-3},
  pages     = {1045 -- 1051},
  year      = {2012},
  abstract  = {The globally threatened Aquatic Warbler Acrocephalus paludicola is a Palearctic-African long-distance migrant that undergoes a complete moult while wintering in Africa. Little is known about the timing of moult and the birds' mobility during moulting periods. We conducted the first study on the moult of Aquatic Warblers, in the Djoudj area of Senegal, West Africa. Wing moult scores from 36 to 90 and raggedness scores from 0 to 25 were recorded in December and January. No moulting Aquatic Warblers were caught after January. Body-feather moult was observed during and shortly after wing moult until January. We conclude that Aquatic Warblers follow the typical sequence of passerine moult, with remige moult starting in October or November. To find out how moult affects their mobility, we measured the net distance that Aquatic Warblers equipped with radio transmitters travelled in 15-min intervals. In our small sample of eight birds, the mean path length was 34 m, and there was no obvious difference between the path lengths in moulting and non-moulting individuals. We conclude that, possibly, moult does not affect the mobility and flight ability of Aquatic Warblers in general. Further research is needed to locate other wintering grounds, e.g. in the Inner Niger Delta, and reproduce our study in other populations.},
  language  = {en}
}
@article{TartivelBehlSchroeteretal.2012,
  author    = {Tartivel, Lucile and Behl, Marc and Schr{\"o}ter, Michael and Lendlein, Andreas},
  title     = {Hydrogel networks based on ABA triblock copolymers},
  series = {Journal of applied biomaterials \& functional materials},
  volume    = {10},
  journal   = {Journal of applied biomaterials \& functional materials},
  number    = {3},
  publisher = {Wichtig},
  address   = {Milano},
  issn      = {2280-8000},
  doi       = {10.5301/JABFM.2012.10295},
  pages     = {243 -- 248},
  year      = {2012},
  abstract  = {Background: Triblock copolymers from hydrophilic oligo(ethylene glycol) segment A and oligo(propylene glycol) segment B, providing an ABA structure (OEG-OPG-OEG triblock), are known to be biocompatible and are used as self-solidifying gels in drug depots. A complete removal of these depots would be helpful in cases of undesired side effects of a drug, but this remains a challenge as they liquefy below their transition temperature. Therefore we describe the synthesis of covalently cross-linked hydrogel networks. Method: Triblock copolymer-based hydrogels were created by irradiating aqueous solutions of the corresponding macro-dimethacrylates with UV light. The degree of swelling, swelling kinetics, mechanical properties and morphology of the networks were investigated. Results: Depending on precursor concentration, equilibrium degree of swelling of the films ranged between 500\% and 880\% and was reached in 1 hour. In addition, values for storage and loss moduli of the hydrogel networks were in the 100 Pa to 10 kPa range. Conclusion: Although OEG-OPG-OEG triblocks are known for their micellization, which could hamper polymer network formation, reactive OEG-OPG-OEG triblock oligomers could be successfully polymerized into hydrogel networks. The degree of swelling of these hydrogels depends on their molecular weight and on the oligomer concentration used for hydrogel preparation. In combination with the temperature sensitivity of the ABA triblock copolymers, it is assumed that such hydrogels might be beneficial for future medical applications -e.g., removable drug release systems.},
  language  = {en}
}
@article{TaalStPourcainThieringetal.2012,
  author    = {Taal, H. Rob and St Pourcain, Beate and Thiering, Elisabeth and Das, Shikta and Mook-Kanamori, Dennis O. and Warrington, Nicole M. and Kaakinen, Marika and Kreiner-Moller, Eskil and Bradfield, Jonathan P. and Freathy, Rachel M. and Geller, Frank and Guxens, Monica and Cousminer, Diana L. and Kerkhof, Marjan and Timpson, Nicholas J. and Ikram, M. Arfan and Beilin, Lawrence J. and Bonnelykke, Klaus and Buxton, Jessica L. and Charoen, Pimphen and Chawes, Bo Lund Krogsgaard and Eriksson, Johan and Evans, David M. and Hofman, Albert and Kemp, John P. and Kim, Cecilia E. and Klopp, Norman and Lahti, Jari and Lye, Stephen J. and McMahon, George and Mentch, Frank D. and Mueller-Nurasyid, Martina and O'Reilly, Paul F. and Prokopenko, Inga and Rivadeneira, Fernando and Steegers, Eric A. P. and Sunyer, Jordi and Tiesler, Carla and Yaghootkar, Hanieh and Breteler, Monique M. B. and Debette, Stephanie and Fornage, Myriam and Gudnason, Vilmundur and Launer, Lenore J. and van der Lugt, Aad and Mosley, Thomas H. and Seshadri, Sudha and Smith, Albert V. and Vernooij, Meike W. and Blakemore, Alexandra I. F. and Chiavacci, Rosetta M. and Feenstra, Bjarke and Fernandez-Banet, Julio and Grant, Struan F. A. and Hartikainen, Anna-Liisa and van der Heijden, Albert J. and Iniguez, Carmen and Lathrop, Mark and McArdle, Wendy L. and Molgaard, Anne and Newnham, John P. and Palmer, Lyle J. and Palotie, Aarno and Pouta, Annneli and Ring, Susan M. and Sovio, Ulla and Standl, Marie and Uitterlinden, Andre G. and Wichmann, H-Erich and Vissing, Nadja Hawwa and DeCarli, Charles and van Duijn, Cornelia M. and McCarthy, Mark I. and Koppelman, Gerard H. and Estivill, Xavier and Hattersley, Andrew T. and Melbye, Mads and Bisgaard, Hans and Pennell, Craig E. and Widen, Elisabeth and Hakonarson, Hakon and Smith, George Davey and Heinrich, Joachim and Jarvelin, Marjo-Riitta and Jaddoe, Vincent W. V. and Adair, Linda S. and Ang, Wei and Atalay, Mustafa and van Beijsterveldt, Toos and Bergen, Nienke and Benke, Kelly and Berry, Diane J. and Bradfield, Jonathan P. and Charoen, Pimphen and Coin, Lachlan and Cousminer, Diana L. and Das, Shikta and Davis, Oliver S. P. and Elliott, Paul and Evans, David M. and Feenstra, Bjarke and Flexeder, Claudia and Frayling, Tim and Freathy, Rachel M. and Gaillard, Romy and Geller, Frank and Groen-Blokhuis, Maria and Goh, Liang-Kee and Guxens, Monica and Haworth, Claire M. A. and Hadley, Dexter and Hebebrand, Johannes and Hinney, Anke and Hirschhorn, Joel N. and Holloway, John W. and Holst, Claus and Hottenga, Jouke Jan and Horikoshi, Momoko and Huikari, Ville and Hypponen, Elina and Iniguez, Carmen and Kaakinen, Marika and Kilpelainen, Tuomas O. and Kirin, Mirna and Kowgier, Matthew and Lakka, Hanna-Maaria and Lange, Leslie A. and Lawlor, Debbie A. and Lehtimaki, Terho and Lewin, Alex and Lindgren, Cecilia and Lindi, Virpi and Maggi, Reedik and Marsh, Julie and Middeldorp, Christel and Millwood, Iona and Mook-Kanamori, Dennis O. and Murray, Jeffrey C. and Nivard, Michel and Nohr, Ellen Aagaard and Ntalla, Ioanna and Oken, Emily and O'Reilly, Paul F. and Palmer, Lyle J. and Panoutsopoulou, Kalliope and Pararajasingham, Jennifer and Prokopenko, Inga and Rodriguez, Alina and Salem, Rany M. and Sebert, Sylvain and Siitonen, Niina and Sovio, Ulla and St Pourcain, Beate and Strachan, David P. and Sunyer, Jordi and Taal, H. Rob and Teo, Yik-Ying and Thiering, Elisabeth and Tiesler, Carla and Uitterlinden, Andre G. and Valcarcel, Beatriz and Warrington, Nicole M. and White, Scott and Willemsen, Gonneke and Yaghootkar, Hanieh and Zeggini, Eleftheria and Boomsma, Dorret I. and Cooper, Cyrus and Estivill, Xavier and Gillman, Matthew and Grant, Struan F. A. and Hakonarson, Hakon and Hattersley, Andrew T. and Heinrich, Joachim and Hocher, Berthold and Jaddoe, Vincent W. V. and Jarvelin, Marjo-Riitta and Lakka, Timo A. and McCarthy, Mark I. and Melbye, Mads and Mohlke, Karen L. and Dedoussis, George V. and Ong, Ken K. and Pearson, Ewan R. and Pennell, Craig E. and Price, Thomas S. and Power, Chris and Raitakari, Olli T. and Saw, Seang-Mei and Scherag, Andre and Simell, Olli and Sorensen, Thorkild I. A. and Timpson, Nicholas J. and Widen, Elisabeth and Wilson, James F. and Ang, Wei and van Beijsterveldt, Toos and Bergen, Nienke and Benke, Kelly and Berry, Diane J. and Bradfield, Jonathan P. and Charoen, Pimphen and Coin, Lachlan and Cousminer, Diana L. and Das, Shikta and Elliott, Paul and Evans, David M. and Frayling, Tim and Freathy, Rachel M. and Gaillard, Romy and Groen-Blokhuis, Maria and Guxens, Monica and Hadley, Dexter and Hottenga, Jouke Jan and Huikari, Ville and Hypponen, Elina and Kaakinen, Marika and Kowgier, Matthew and Lawlor, Debbie A. and Lewin, Alex and Lindgren, Cecilia and Marsh, Julie and Middeldorp, Christel and Millwood, Iona and Mook-Kanamori, Dennis O. and Nivard, Michel and O'Reilly, Paul F. and Palmer, Lyle J. and Prokopenko, Inga and Rodriguez, Alina and Sebert, Sylvain and Sovio, Ulla and St Pourcain, Beate and Standl, Marie and Strachan, David P. and Sunyer, Jordi and Taal, H. Rob and Thiering, Elisabeth and Tiesler, Carla and Uitterlinden, Andre G. and Valcarcel, Beatriz and Warrington, Nicole M. and White, Scott and Willemsen, Gonneke and Yaghootkar, Hanieh and Boomsma, Dorret I. and Estivill, Xavier and Grant, Struan F. A. and Hakonarson, Hakon and Hattersley, Andrew T. and Heinrich, Joachim and Jaddoe, Vincent W. V. and Jarvelin, Marjo-Riitta and McCarthy, Mark I. and Pennell, Craig E. and Power, Chris and Timpson, Nicholas J. and Widen, Elisabeth and Ikram, M. Arfan and Fornage, Myriam and Smith, Albert V. and Seshadri, Sudha and Schmidt, Reinhold and Debette, Stephanie and Vrooman, Henri A. and Sigurdsson, Sigurdur and Ropele, Stefan and Coker, Laura H. and Longstreth, W. T. and Niessen, Wiro J. and DeStefano, Anita L. and Beiser, Alexa and Zijdenbos, Alex P. and Struchalin, Maksim and Jack, Clifford R. and Nalls, Mike A. and Au, Rhoda and Hofman, Albert and Gudnason, Haukur and van der Lugt, Aad and Harris, Tamara B. and Meeks, William M. and Vernooij, Meike W. and van Buchem, Mark A. and Catellier, Diane and Gudnason, Vilmundur and Windham, B. Gwen and Wolf, Philip A. and van Duijn, Cornelia M. and Mosley, Thomas H. and Schmidt, Helena and Launer, Lenore J. and Breteler, Monique M. B. and DeCarli, Charles},
  title     = {Common variants at 12q15 and 12q24 are associated with infant head circumference},
  series = {Nature genetics},
  volume    = {44},
  journal   = {Nature genetics},
  number    = {5},
  publisher = {Nature Publ. Group},
  address   = {New York},
  organization    = {Cohorts Heart Aging Res Genetic Ep, Early Genetics Lifecourse Epidemio, Early Growth Genetics EGG Consorti},
  issn      = {1061-4036},
  doi       = {10.1038/ng.2238},
  pages     = {532 -- +},
  year      = {2012},
  abstract  = {To identify genetic variants associated with head circumference in infancy, we performed a meta-analysis of seven genome-wide association studies (GWAS) (N = 10,768 individuals of European ancestry enrolled in pregnancy and/or birth cohorts) and followed up three lead signals in six replication studies (combined N = 19,089). rs7980687 on chromosome 12q24 (P = 8.1 x 10(-9)) and rs1042725 on chromosome 12q15 (P = 2.8 x 10(-10)) were robustly associated with head circumference in infancy. Although these loci have previously been associated with adult height(1), their effects on infant head circumference were largely independent of height (P = 3.8 x 10(-7) for rs7980687 and P = 1.3 x 10(-7) for rs1042725 after adjustment for infant height). A third signal, rs11655470 on chromosome 17q21, showed suggestive evidence of association with head circumference (P = 3.9 x 10(-6)). SNPs correlated to the 17q21 signal have shown genome-wide association with adult intracranial volume(2), Parkinson's disease and other neurodegenerative diseases(3-5), indicating that a common genetic variant in this region might link early brain growth with neurological disease in later life.},
  language  = {en}
}
@article{StoofLeichsenringEppTrauthetal.2012,
  author    = {Stoof-Leichsenring, Kathleen Rosemarie and Epp, Laura Saskia and Trauth, Martin H. and Tiedemann, Ralph},
  title     = {Hidden diversity in diatoms of Kenyan Lake Naivasha a genetic approach detects temporal variation},
  series = {Molecular ecology},
  volume    = {21},
  journal   = {Molecular ecology},
  number    = {8},
  publisher = {Wiley-Blackwell},
  address   = {Malden},
  issn      = {0962-1083},
  doi       = {10.1111/j.1365-294X.2011.05412.x},
  pages     = {1918 -- 1930},
  year      = {2012},
  abstract  = {This study provides insights into the morphological and genetic diversity in diatoms occurring in core sediments from tropical lakes in Kenya. We developed a genetic survey technique specific for diatoms utilizing a short region (7667 bp) of the ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL) gene as genetic barcode. Our analyses (i) validated the use of rbcL as a barcoding marker for diatoms, applied to sediment samples, (ii) showed a significant correlation between the results obtained by morphological and molecular data and (iii) indicated temporal variation in diatom assemblages on the inter- and intra-specific level. Diatom assemblages from a short core from Lake Naivasha show a drastic shift over the last 200 years, as littoral species (e.g. Navicula) are replaced by more planktonic ones (e.g. Aulacoseira). Within that same period, we detected periodic changes in the respective frequencies of distinct haplotype groups of Navicula, which coincide with wet and dry periods of Lake Naivasha between 1820 and 1938 AD. Our genetic analyses on historical lake sediments revealed inter- and intra-specific variation in diatoms, which is partially hidden behind single morphotypes. The occurrence of particular genetic lineages is probably correlated with environmental factors.},
  language  = {en}
}
@article{StojanovicMarkovicKleinpeteretal.2012,
  author    = {Stojanovic, Milovan and Markovic, Rade and Kleinpeter, Erich and Baranac-Stojanovic, Marija},
  title     = {Synthesis of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions},
  series = {Organic \& biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry},
  volume    = {10},
  journal   = {Organic \& biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry},
  number    = {3},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1477-0520},
  doi       = {10.1039/c1ob06451g},
  pages     = {575 -- 589},
  year      = {2012},
  abstract  = {Syntheses of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions incorporating heteroatom-based nucleophiles have been examined and discussed. The formation of (5,6)-membered systems was feasible with all nucleophiles tried (O, S and N), while the closing of the five-membered ring was restricted to O- and S-nucleophiles. The closure of a four-membered ring failed. Instead, the bicyclic (5,6)-membered acetal derivative and the tricyclic system with an eight-membered central ring were obtained from the substrates containing O and S nucleophilic moieties, respectively. The reaction outcome and stereochemistry are rationalized using quantum chemical calculations at B3LYP/6-31G(d) level. The exclusive cis-stereoselectivity in the formation of (5,6)- and (5,5)-membered systems results from thermodynamic control, whereas the formation of the eight-membered ring was kinetically controlled.},
  language  = {en}
}
@article{StechMerkSchenketal.2012,
  author    = {Stech, Marlitt and Merk, Helmut and Schenk, J{\"o}rg A. and St{\"o}cklein, Walter F. M. and W{\"u}stenhagen, Doreen Anja and Micheel, Burkhard and Duschl, Claus and Bier, Frank Fabian and Kubick, Stefan},
  title     = {Production of functional antibody fragments in a vesicle-based eukaryotic cell-free translation system},
  series = {Journal of biotechnology},
  volume    = {164},
  journal   = {Journal of biotechnology},
  number    = {2},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0168-1656},
  doi       = {10.1016/j.jbiotec.2012.08.020},
  pages     = {220 -- 231},
  year      = {2012},
  abstract  = {Cell-free protein synthesis is of increasing interest for the rapid and high-throughput synthesis of many proteins, in particular also antibody fragments. In this study, we present a novel strategy for the production of single chain antibody fragments (scFv) in a eukaryotic in vitro translation system. This strategy comprises the cell-free expression, isolation and label-free interaction analysis of a model antibody fragment synthesized in two differently prepared insect cell lysates. These lysates contain translocationally active microsomal structures derived from the endoplasmic reticulum (ER), allowing for posttranslational modifications of cell-free synthesized proteins. Both types of these insect cell lysates enable the synthesis and translocation of scFv into ER-derived vesicles. However, only the one that has a specifically adapted redox potential yields functional active antibody fragments. We have developed a new methodology for the isolation of functional target proteins based on the translocation of cell-free produced scFv into microsomal structures and subsequent collection of protein-enriched vesicles. Antibody fragments that have been released from these vesicles are shown to be well suited for label-free binding studies. Altogether, these results show the potential of insect cell lysates for the production, purification and selection of antibody fragments in an easy-to-handle and time-saving manner.},
  language  = {en}
}
@article{SprussHenkelKanurietal.2012,
  author    = {Spruss, Astrid and Henkel, Janin and Kanuri, Giridhar and Blank, Daniela and P{\"u}schel, Gerhard Paul and Bischoff, Stephan C. and Bergheim, Ina},
  title     = {Female mice are more susceptible to nonalcoholic fatty liver disease sex-specific regulation of the hepatic AMP-Activated protein Kinase-Plasminogen activator inhibitor 1 cascade, but not the hepatic endotoxin response},
  series = {Molecular medicine},
  volume    = {18},
  journal   = {Molecular medicine},
  number    = {9},
  publisher = {Feinstein Inst. for Medical Research},
  address   = {Manhasset},
  issn      = {1076-1551},
  doi       = {10.2119/molmed.2012.00223},
  pages     = {1346 -- 1355},
  year      = {2012},
  abstract  = {As significant differences between sexes were found in the susceptibility to alcoholic liver disease in human and animal models, it was the aim of the present study to investigate whether female mice also are more susceptible to the development of nonalcoholic fatty liver disease (NAFLD). Male and female C57BL/6J mice were fed either water or 30\% fructose solution ad libitum for 16 wks. Liver damage was evaluated by histological scoring. Portal endotoxin levels and markers of Kupffer cell activation and insulin resistance, plasminogen activator inhibitor 1 (PAI-1) and phosphorylated adenosine monophosphate-activated protein kinase (pAMPK) were measured in the liver. Adiponectin mRNA expression was determined in adipose tissue. Hepatic steatosis was almost similar between male and female mice; however, inflammation was markedly more pronounced in livers of female mice. Portal endotoxin levels, hepatic levels of myeloid differentiation primary response gene (88) (MyD88) protein and of 4-hydroxynonenal protein adducts were elevated in animals with NAFLD regardless of sex. Expression of insulin receptor substrate 1 and 2 was decreased to a similar extent in livers of male and female mice with NAFLD. The less pronounced susceptibility to liver damage in male mice was associated with a superinduction of hepatic pAMPK in these mice whereas, in livers of female mice with NAFLD, PAI-1 was markedly induced. Expression of adiponectin in visceral fat was significantly lower in female mice with NAFLD but unchanged in male mice compared with respective controls. In conclusion, our data suggest that the sex-specific differences in the susceptibility to NAFLD are associated with differences in the regulation of the adiponectin-AMPK-PAI-1 signaling cascade. Online address: http://www.molmed.Org doi: 10.2119/molmed.2012.00223},
  language  = {en}
}
@article{SpijkermanWackerWeithoffetal.2012,
  author    = {Spijkerman, Elly and Wacker, Alexander and Weithoff, Guntram and Leya, Thomas},
  title     = {Elemental and fatty acid composition of snow algae in Arctic habitats},
  series = {Frontiers in microbiology},
  volume    = {3},
  journal   = {Frontiers in microbiology},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-302X},
  doi       = {10.3389/fmicb.2012.00380},
  pages     = {15},
  year      = {2012},
  abstract  = {Red, orange or green snow is the macroscopic phenomenon comprising different eukaryotic algae. Little is known about the ecology and nutrient regimes in these algal communities. Therefore, eight snow algal communities from five intensively tinted snow fields in western Spitsbergen were analysed for nutrient concentrations and fatty acid (FA) composition. To evaluate the importance of a shift from green to red forms on the FA-variability of the field samples, four snow algal strains were grown under nitrogen replete and moderate light (+N+ML) or N-limited and high light (-N+HL) conditions. All eight field algal communities were dominated by red and orange cysts. Dissolved nutrient concentration of the snow revealed a broad range of NH4+ (<0.005-1.2 mg NI-1) and only low PO43- (< 18 mu g P I-1) levels. The external nutrient concentration did not reflect cellular nutrient ratios as C:N and C:P ratios of the communities were highest at locations containing relatively high concentrations of NH4- and PO43-. Molar N:P ratios ranged from 11 to 21 and did not suggest clear limitation of a single nutrient. On a per carbon basis, we found a 6-fold difference in total FA content between the eight snow algal communities, ranging from 50 to 300 mg FA g C-1. In multivariate analyses total FA content opposed the cellular N:C quota and a large part of the FA variability among field locations originated from the abundant FAs C181n-9, C18 2n-6, and C183n-3. Both field samples and snow algal strains grown under -N+HL conditions had high concentrations of C181n-9. FAs possibly accumulated due to the cessation of growth. Differences in color and nutritional composition between patches of snow algal communities within one snow field were not directly related to nutrient conditions. We propose that the highly patchy distribution of snow algae within and between snow fields may also result from differences in topographical and geological parameters such as slope, melting water rivulets, and rock formation.},
  language  = {en}
}
@article{SperfeldWacker2012,
  author    = {Sperfeld, Erik and Wacker, Alexander},
  title     = {Temperature affects the limitation of Daphnia magna by eicosapentaenoic acid, and the fatty acid composition of body tissue and eggs},
  series = {Freshwater biology},
  volume    = {57},
  journal   = {Freshwater biology},
  number    = {3},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0046-5070},
  doi       = {10.1111/j.1365-2427.2011.02719.x},
  pages     = {497 -- 508},
  year      = {2012},
  abstract  = {1. Poikilothermic animals incorporate more polyunsaturated fatty acids (PUFAs) into their cellular membranes as temperature declines, suggesting an increased sensitivity to PUFA limitation in cool conditions. To test this we raised Daphnia magna at different temperatures and investigated the effect of varying dietary PUFA on life history parameters (i.e. growth, reproduction) and the PUFA composition of body tissue and eggs. 2. Upon a PUFA-rich diet (Cryptomonas sp.) females showed higher concentrations of several omega 3 PUFAs in their body tissue at 15 degrees C than at 20 degrees C and 25 degrees C, indicating a greater structural requirement for omega 3 PUFAs at low temperature. Their eggs had an equal but higher concentration of omega 3 PUFAs than their body tissue. 3. In a life history experiment at 15 and 20 degrees C we supplemented a diet of a PUFA-free cyanobacterium with the omega 3 PUFA eicosapentaenoic acid (EPA). The growth of D. magna was more strongly EPA limited at low temperature. A greater requirement for structural EPA at 15 degrees C was indicated by a steeper increase in somatic EPA content with dietary EPA compared to 20 degrees C. 4. At 20 degrees C the development of eggs to successful hatching was high when EPA was supplied to the mothers. At 15 degrees C the hatching success was generally poor, despite of a higher maternal provision of EPA to eggs, compared to that at 20 degrees C, suggesting that EPA alone was insufficient for proper neonatal development at the low temperature. The growth of offspring from mothers raised at 20 degrees C without EPA supplementation was very low, indicating that the negative effects of EPA deficiency can be carried on to the next generation. 5. The fatty acid composition of Daphnia sp. in published field studies shows increasing proportions of saturated fatty acids with increasing environmental temperature, whereas omega 3 PUFAs and EPA show no clear pattern, suggesting that variations in dietary PUFA may mask temperature-dependent adjustments in omega 3 PUFA concentrations of cladocerans in nature.},
  language  = {en}
}
@article{SperfeldMartinCreuzburgWacker2012,
  author    = {Sperfeld, Erik and Martin-Creuzburg, Dominik and Wacker, Alexander},
  title     = {Multiple resource limitation theory applied to herbivorous consumers Liebig's minimum rule vs. interactive co-limitation},
  series = {Ecology letters},
  volume    = {15},
  journal   = {Ecology letters},
  number    = {2},
  publisher = {Wiley-Blackwell},
  address   = {Malden},
  issn      = {1461-023X},
  doi       = {10.1111/j.1461-0248.2011.01719.x},
  pages     = {142 -- 150},
  year      = {2012},
  abstract  = {There is growing consensus that the growth of herbivorous consumers is frequently limited by more than one nutrient simultaneously. This understanding, however, is based primarily on theoretical considerations and the applicability of existing concepts of co-limitation has rarely been tested experimentally. Here, we assessed the suitability of two contrasting concepts of resource limitation, i.e. Liebigs minimum rule and the multiple limitation hypothesis, to describe nutrient-dependent growth responses of a freshwater herbivore (Daphnia magna) in a system with two potentially limiting nutrients (cholesterol and eicosapentaenoic acid). The results indicated that these essential nutrients interact, and do not strictly follow Liebigs minimum rule, which consistently overestimates growth at co-limiting conditions and thus is not applicable to describe multiple nutrient limitation of herbivorous consumers. We infer that the outcome of resource-based modelling approaches assessing herbivore population dynamics strongly depends on the applied concept of co-limitation.},
  language  = {en}
}
@article{SpeckHeckyTametal.2012,
  author    = {Speck, Janina and Hecky, Jochen and Tam, Heng-Keat and Arndt, Katja Maren and Einsle, Oliver and M{\"u}ller, Kristian M.},
  title     = {Exploring the molecular linkage of protein stability traits for enzyme optimization by iterative truncation and evolution},
  series = {Biochemistry},
  volume    = {51},
  journal   = {Biochemistry},
  number    = {24},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0006-2960},
  doi       = {10.1021/bi2018738},
  pages     = {4850 -- 4867},
  year      = {2012},
  abstract  = {The stability of proteins is paramount for their therapeutic and industrial use and, thus, is a major task for protein engineering. Several types of chemical and physical stabilities are desired, and discussion revolves around whether each stability trait needs to be addressed separately and how specific and compatible stabilizing mutations act. We demonstrate a stepwise perturbation-compensation strategy, which identifies mutations rescuing the activity of a truncated TEM beta-lactamase. Analyses relating structural stress with the external stresses of heat, denaturants, and proteases reveal our second-site suppressors as general stability centers that also improve the full-length enzyme. A library of lactamase variants truncated by 15 N-terminal and three C-terminal residues (Bla-N Delta 15C Delta 3) was subjected to activity selection and DNA shuffling. The resulting clone with the best in vivo performance harbored eight mutations, surpassed the full-length wild-type protein by 5.3 degrees C in T-m, displayed significantly higher catalytic activity at elevated temperatures, and showed delayed guanidine-induced denaturation. The crystal structure of this mutant was determined and provided insights into its stability determinants. Stepwise reconstitution of the N- and C-termini increased its thermal, denaturant, and proteolytic resistance successively, leading to a full-length enzyme with a T-m increased by 15.3 degrees C and a half-denaturation concentration shifted from 0.53 to 1.75 M guanidinium relative to that of the wild type. These improvements demonstrate that iterative truncation-optimization cycles can exploit stability-trait linkages in proteins and are exceptionally suited for the creation of progressively stabilized variants and/or downsized proteins without the need for detailed structural or mechanistic information.},
  language  = {en}
}
@article{SoyezReinhold2012,
  author    = {Soyez, Konrad and Reinhold, J{\"u}rgen},
  title     = {Biowaste treatment - recycling potential for humus reproduction},
  series = {Chemie - Ingenieur - Technik},
  volume    = {84},
  journal   = {Chemie - Ingenieur - Technik},
  number    = {7},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0009-286X},
  doi       = {10.1002/cite.201100247},
  pages     = {991 -- 998},
  year      = {2012},
  abstract  = {The majority of the annually accumulated 9 million t of organics in municipal solid waste is recycled. Amongst the technological options composting is most important. 15\% are treated by digestion and result in both biogas as a renewable energy source and organic residues. Compost contains considerable amounts of minerals and organic carbon which can substitute fertilizers including organic compounds. Application of compost for the reproduction of humus in soils is its most important effect. Scientifically, the applicability of the humus balancing method developed by VDLUFA is proven. It balances input and output of organic carbon during cultivation and harvest. Optimum level of humus which is a specific fixed value for each type of soils is therefore realized. An energy humus index is proposed, which may indicate preferred usage of organics as fertilizer or renewable energy source.},
  language  = {de}
}
@article{SonnenscheinSyitGrossartetal.2012,
  author    = {Sonnenschein, Eva C. and Syit, Desalegne Abebew and Grossart, Hans-Peter and Ullrich, Matthias S.},
  title     = {Chemotaxis of Marinobacter adhaerens and Its Impact on Attachment to the Diatom Thalassiosira weissflogii},
  series = {Applied and environmental microbiology},
  volume    = {78},
  journal   = {Applied and environmental microbiology},
  number    = {19},
  publisher = {American Society for Microbiology},
  address   = {Washington},
  issn      = {0099-2240},
  doi       = {10.1128/AEM.01790-12},
  pages     = {6900 -- 6907},
  year      = {2012},
  abstract  = {Alga-bacterium interactions are crucial for aggregate formation and carbon cycling in aquatic systems. To understand the initiation of these interactions, we investigated bacterial chemotaxis within a bilateral model system. Marinobacter adhaerens HP15 has been demonstrated to attach to the diatom Thalassiosira weissflogii and induce transparent exopolymeric particle and aggregate formation. M. adhaerens possesses one polar flagellum and is highly motile. Bacterial cells were attracted to diatom cells, as demonstrated by addition of diatom cell homogenate or diatom culture supernatant to soft agar, suggesting that chemotaxis might be important for the interaction of M. adhaerens with diatoms. Three distinct chemotaxis-associated gene clusters were identified in the genome sequence of M. adhaerens, with the clusters showing significant sequence similarities to those of Pseudomonas aeruginosa PAO1. Mutations in the genes cheA, cheB, chpA, and chpB, which encode histidine kinases and methylesterases and which are putatively involved in either flagellum-associated chemotaxis or pilus-mediated twitching motility, were generated and mutants with the mutations were phenotypically analyzed. Delta cheA and Delta cheB mutants were found to be swimming deficient, and all four mutants were impaired in biofilm formation on abiotic surfaces. Comparison of the HP15 wild type and its chemotaxis mutants in cocultures with the diatom revealed that the fraction of bacteria attaching to the diatom decreased significantly for mutants in comparison to that for the wild type. Our results highlight the importance of M. adhaerens chemotaxis in initiation of its interaction with the diatom. In-depth knowledge of these basic processes in interspecies interactions is pivotal to obtain a systematic understanding of organic matter flux and nutrient cycling in marine ecosystems.},
  language  = {en}
}
@article{SocherPratiBochetal.2012,
  author    = {Socher, Stephanie A. and Prati, Daniel and Boch, Steffen and M{\"u}ller, J{\"o}rg and Klaus, Valentin H. and H{\"o}lzel, Norbert and Fischer, Markus},
  title     = {Direct and productivity-mediated indirect effects of fertilization, mowing and grazing on grassland species richness},
  series = {The journal of ecology},
  volume    = {100},
  journal   = {The journal of ecology},
  number    = {6},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0022-0477},
  doi       = {10.1111/j.1365-2745.2012.02020.x},
  pages     = {1391 -- 1399},
  year      = {2012},
  abstract  = {Recent declines in biodiversity have given new urgency to questions about the relationship between land-use change, biodiversity and ecosystem processes. Despite the existence of a large body of research on the effects of land use on species richness, it is unclear whether the effects of land use on species richness are principally direct or indirect, mediated by concomitant changes in ecosystem processes. Therefore, we compared the direct effects of land use (fertilization, mowing and grazing) on species richness with indirect ones (mediated via grassland productivity) for grasslands in central Europe. We measured the richness and above-ground biomass in 150 grassland plots in 3 regions of Germany (the so-called Biodiversity Exploratories). We used univariate and structural equation models to examine direct and indirect land-use effects. The direct effects of mowing (-0.37, effect size) and grazing (0.04) intensity on species richness were stronger compared with the indirect effects of mowing (-0.04) and grazing (-0.01). However, the strong negative effect of fertilization (-0.23) on species richness was mainly indirect, mediated by increased productivity compared with the weak direct negative effect (-0.07). Differences between regions in land-use effects showed five times weaker negative effects of mowing (-0.13) in the region with organic soils (Schorfheide-Chorin), strong overall negative effects of grazing (-0.29) for the region with organic soils opposed to a similar strong positive effect (0.30) in the Hainich-Dun region, whereas the Schwabische Alb region displayed a five times weaker positive effect (0.06) only. Further, fertilization effects on species richness were positive (0.03) for the region with organic soils compared to up to 25 times stronger negative effects in the other two regions. Synthesis. Our results clearly show the importance of studying both direct and indirect effects of land-use intensity. They demonstrate the indirect nature, via productivity, of the negative effect of fertilization intensity on plant species richness in the real-world context of management-induced gradients of intensity of fertilization, mowing and grazing. Finally, they highlight that careful consideration of regional environments is necessary before attempting to generalize land-use effects on species diversity.},
  language  = {en}
}
@phdthesis{Smirnova2012,
  author    = {Smirnova, Julia},
  title     = {Carbohydrate-active enzymes metabolising maltose: kinetic and structural features},
  address   = {Potsdam},
  pages     = {162 S.},
  year      = {2012},
  language  = {en}
}
@article{SivanesanKalaivaniFischeretal.2012,
  author    = {Sivanesan, Arumugam and Kalaivani, Govindasamy and Fischer, Anna and Stiba, Konstanze and Leimk{\"u}hler, Silke and Weidinger, Inez M.},
  title     = {Complementary surface-enhanced resonance raman Spectroscopic Biodetection of mixed protein solutions by Chitosan- and Silica-Coated Plasmon-Tuned Silver Nanoparticles},
  series = {Analytical chemistry},
  volume    = {84},
  journal   = {Analytical chemistry},
  number    = {13},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0003-2700},
  doi       = {10.1021/ac301001a},
  pages     = {5759 -- 5764},
  year      = {2012},
  abstract  = {Silver nanoparticles with identical plasmonic properties but different surface functionalities are synthesized and tested as chemically selective surface-enhanced resonance Raman (SERR) amplifiers in a two-component protein solution. The surface plasmon resonances of the particles are tuned to 413 nm to match the molecular resonance of protein heme cofactors. Biocompatible functionalization of the nanoparticles with a thin film of chitosan yields selective SERR enhancement of the anionic protein cytochrome b(5), whereas functionalization with SiO2 amplifies only the spectra of the cationic protein cytochrome c. As a result, subsequent addition of the two differently functionalized particles yields complementary information on the same mixed protein sample solution. Finally, the applicability of chitosan-coated Ag nanoparticles for protein separation was tested by in situ resonance Raman spectroscopy.},
  language  = {en}
}
@article{SilvaIturrizaKetmaierTiedemann2012,
  author    = {Silva-Iturriza, Adriana and Ketmaier, Valerio and Tiedemann, Ralph},
  title     = {Profound population structure in the Philippine Bulbul Hypsipetes philippinus (Pycnonotidae, Ayes) is not reflected in its Haemoproteus haemosporidian parasite},
  series = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics and infectious diseases (MEEGID)},
  volume    = {12},
  journal   = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics and infectious diseases (MEEGID)},
  number    = {1},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1567-1348},
  doi       = {10.1016/j.meegid.2011.10.024},
  pages     = {127 -- 136},
  year      = {2012},
  abstract  = {In this study we used molecular markers to screen for the occurrence and prevalence of the three most common haemosporidian genera (Haemoproteus, Plasmodium, and Leucocytozoon) in blood samples of the Philippine Bulbul (Hypsipetes philippinus), a thrush-size passerine bird endemic to the Philippine Archipelago. We then used molecular data to ask whether the phylogeographic patterns in this insular host-parasite system might follow similar evolutionary trajectories or not. We took advantage of a previous study describing the pattern of genetic structuring in the Philippine Bulbul across the Central Philippine Archipelago (6 islands, 7 populations and 58 individuals; three mitochondrial DNA genes). The very same birds were here screened for the occurrence of parasites by species-specific PCR assays of the mitochondrial cytochrome b gene (471 base pairs). Twenty-eight out of the 58 analysed birds had Haemoproteus (48\%) infections while just 2\% of the birds were infected with either Leucocytozoon or Plasmodium. Sixteen of the 28 birds carrying Haemoproteus had multiple infections. The phylogeography of the Philippine Bulbul mostly reflects the geographical origin of samples and it is consistent with the occurrence of two different subspecies on (1) Semirara and (2) Carabao, Boracay, North Gigante, Panay, and Negros, respectively. Haemoproteus phylogeography shows very little geographical structure, suggesting extensive gene flow among locations. While movements of birds among islands seem very sporadic, we found co-occurring evolutionary divergent parasite lineages. We conclude that historical processes have played a major role in shaping the host phylogeography, while they have left no signature in that of the parasites. Here ongoing population processes, possibly multiple reinvasions mediated by other hosts, are predominant.},
  language  = {en}
}