@phdthesis{Strehmel2010, author = {Strehmel, Nadine}, title = {GC-TOF-MS basierte Analyse von niedermolekularen Prim{\"a}r- und Sekund{\"a}rmetaboliten agrarwirtschaftlich bedeutsamer Nutzpflanzen}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-51238}, school = {Universit{\"a}t Potsdam}, year = {2010}, abstract = {Die Qualit{\"a}t von Nutzpflanzen ist von zahlreichen Einflussfaktoren wie beispielsweise Lagerbedingungen und Sorteneigenschaften abh{\"a}ngig. Um Qualit{\"a}tsm{\"a}ngel zu minimieren und Absatzchancen von Nutzpflanzen zu steigern sind umfangreiche Analysen hinsichtlich ihrer stofflichen Zusammensetzung notwendig. Chromatographische Techniken gekoppelt an ein Massenspektrometer und die Kernspinresonanzspektroskopie wurden daf{\"u}r bislang verwendet. In der vorliegenden Arbeit wurde ein Gaschromatograph an ein Flugzeitmassenspektrometer (GC-TOF-MS) gekoppelt, um physiologische Prozesse bzw. Eigenschaften (die Schwarzfleckigkeit, die Chipsbr{\"a}unung, das Physiologische Alter und die Keimhemmung) von Nutzpflanzen aufzukl{\"a}ren. Als Pflanzenmodell wurde daf{\"u}r die Kartoffelknolle verwendet. Dazu wurden neue analytische L{\"o}sungsans{\"a}tze entwickelt, die eine zielgerichtete Auswertung einer Vielzahl von Proben, die Etablierung einer umfangreichen Referenzspektrenbibliothek und die sichere Archivierung aller experimentellen Daten umfassen. Das Verfahren der Probenvorbereitung wurde soweit modifiziert, dass gering konzentrierte Substanzen mittels GC-TOF-MS analysiert werden k{\"o}nnen. Dadurch wurde das durch die Probenvorbereitung limitierte Substanzspektrum erweitert. Anhand dieser L{\"o}sungsans{\"a}tze wurden physiologisch relevante Stoffwechselprodukte identifiziert, welche indikativ (klassifizierend) bzw. pr{\"a}diktiv (vorhersagend) f{\"u}r die physiologischen Prozesse sind. F{\"u}r die Schwarzfleckigkeitsneigung und die Chipseignung wurde jeweils ein biochemisches Modell zur Vorhersage dieser Prozesse aufgestellt und auf eine Z{\"u}chtungspopulation {\"u}bertragen. Ferner wurden f{\"u}r die Schwarzfleckigkeit Stoffwechselprodukte des Respirationsstoffwechsels identifiziert sowie Aminos{\"a}uren, Glycerollipide und Phenylpropanoide f{\"u}r das Physiologische Alter als relevant erachtet. Das physiologische Altern konnte durch die Anwendung h{\"o}herer Temperaturen beschleunigt werden. Durch Anwendung von Keimhemmern (K{\"u}mmel{\"o}l, Chlorpropham) wurde eine Verz{\"o}gerung des physiologischen Alterns beobachtet. Die Applikation von K{\"u}mmel{\"o}l erwies sich dabei als besonders vorteilhaft. K{\"u}mmel{\"o}l behandelte Knollen wiesen im Vergleich zu unbehandelten Knollen nur Ver{\"a}nderungen im Aminos{\"a}ure-, Zucker- und Sekund{\"a}rstoffwechsel auf. Chlorpropham behandelte Knollen wiesen einen {\"a}hnlichen Stoffwechsel wie die unbehandelten Knollen auf. F{\"u}r die bislang noch nicht identifizierten Stoffwechselprodukte wurden im Rahmen dieser Arbeit das Verfahren der „gezielten An-/Abreicherung", der „gepaarten NMR/GC-TOF-MS Analyse" und das „Entscheidungsbaumverfahren" entwickelt. Diese erm{\"o}glichen eine Klassifizierung von GC-MS Signalen im Hinblick auf ihre chemische Funktionalit{\"a}t. Das Verfahren der gekoppelten NMR/GC-TOF-MS Analyse erwies sich dabei als besonders erfolgversprechend, da es eine Aufkl{\"a}rung bislang unbekannter gaschromatographischer Signale erm{\"o}glicht. In der vorliegenden Arbeit wurden neue Stoffwechselprodukte in der Kartoffelknolle identifiziert, wodurch ein wertvoller Beitrag zur Analytik der Metabolomik geleistet wurde.}, language = {de} } @article{MeyerMatissekMuelleretal.2014, author = {Meyer, S{\"o}ren and Matissek, M. and M{\"u}ller, Sandra Marie and Taleshi, M. S. and Ebert, Franziska and Francesconi, Kevin A. and Schwerdtle, Tanja}, title = {In vitro toxicological characterisation of three arsenic-containing hydrocarbons}, series = {Metallomics}, volume = {2014}, journal = {Metallomics}, number = {6}, issn = {1756-591X}, doi = {10.1039/c4mt00061g}, pages = {1023 -- 1033}, year = {2014}, abstract = {Arsenic-containing hydrocarbons are one group of fat-soluble organic arsenic compounds (arsenolipids) found in marine fish and other seafood. A risk assessment of arsenolipids is urgently needed, but has not been possible because of the total lack of toxicological data. In this study the cellular toxicity of three arsenic-containing hydrocarbons was investigated in cultured human bladder (UROtsa) and liver (HepG2) cells. Cytotoxicity of the arsenic-containing hydrocarbons was comparable to that of arsenite, which was applied as the toxic reference arsenical. A large cellular accumulation of arsenic, as measured by ICP-MS/MS, was observed after incubation of both cell lines with the arsenolipids. Moreover, the toxic mode of action shown by the three arsenic-containing hydrocarbons seemed to differ from that observed for arsenite. Evidence suggests that the high cytotoxic potential of the lipophilic arsenicals results from a decrease in the cellular energy level. This first in vitro based risk assessment cannot exclude a risk to human health related to the presence of arsenolipids in seafood, and indicates the urgent need for further toxicity studies in experimental animals to fully assess this possible risk.}, language = {en} } @misc{MeyerMatissekMuelleretal.2014, author = {Meyer, S{\"o}ren and Matissek, M. and M{\"u}ller, Sandra Marie and Taleshi, M. S. and Ebert, Franziska and Francesconi, Kevin A. and Schwerdtle, Tanja}, title = {In vitro toxicological characterisation of three arsenic-containing hydrocarbons}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-74201}, pages = {1023 -- 1033}, year = {2014}, abstract = {Arsenic-containing hydrocarbons are one group of fat-soluble organic arsenic compounds (arsenolipids) found in marine fish and other seafood. A risk assessment of arsenolipids is urgently needed, but has not been possible because of the total lack of toxicological data. In this study the cellular toxicity of three arsenic-containing hydrocarbons was investigated in cultured human bladder (UROtsa) and liver (HepG2) cells. Cytotoxicity of the arsenic-containing hydrocarbons was comparable to that of arsenite, which was applied as the toxic reference arsenical. A large cellular accumulation of arsenic, as measured by ICP-MS/MS, was observed after incubation of both cell lines with the arsenolipids. Moreover, the toxic mode of action shown by the three arsenic-containing hydrocarbons seemed to differ from that observed for arsenite. Evidence suggests that the high cytotoxic potential of the lipophilic arsenicals results from a decrease in the cellular energy level. This first in vitro based risk assessment cannot exclude a risk to human health related to the presence of arsenolipids in seafood, and indicates the urgent need for further toxicity studies in experimental animals to fully assess this possible risk.}, language = {en} } @misc{MeyerSchulzJeibmannetal.2014, author = {Meyer, S{\"o}ren and Schulz, Jacqueline and Jeibmann, Astrid and Taleshi, Mojtaba S. and Ebert, Franziska and Francesconi, Kevin and Schwerdtle, Tanja}, title = {Arsenic-containing hydrocarbons are toxic in the in vivo model Drosophila melanogaster}, volume = {11}, number = {6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-76819}, pages = {2010 -- 2014}, year = {2014}, abstract = {Arsenic-containing hydrocarbons (AsHC) constitute one group of arsenolipids that have been identified in seafood. In this first in vivo toxicity study for AsHCs, we show that AsHCs exert toxic effects in Drosophila melanogaster in a concentration range similar to that of arsenite. In contrast to arsenite, however, AsHCs cause developmental toxicity in the late developmental stages of Drosophila melanogaster. This work illustrates the need for a full characterisation of the toxicity of AsHCs in experimental animals to finally assess the risk to human health related to the presence of arsenolipids in seafood.}, language = {en} } @article{MeyerSchulzJeibmannetal.2014, author = {Meyer, S{\"o}ren and Schulz, Jacqueline and Jeibmann, Astrid and Taleshi, Mojtaba S. and Ebert, Franziska and Francesconi, Kevin and Schwerdtle, Tanja}, title = {Arsenic-containing hydrocarbons are toxic in the in vivo model Drosophila melanogaster}, series = {Metallomics}, journal = {Metallomics}, editor = {Schwerdtle, Tanja}, publisher = {The Royal Society of Chemistry}, address = {Cambridge}, issn = {1756-5901}, pages = {2010 -- 2014}, year = {2014}, abstract = {Arsenic-containing hydrocarbons (AsHC) constitute one group of arsenolipids that have been identified in seafood. In this first in vivo toxicity study for AsHCs, we show that AsHCs exert toxic effects in Drosophila melanogaster in a concentration range similar to that of arsenite. In contrast to arsenite, however, AsHCs cause developmental toxicity in the late developmental stages of Drosophila melanogaster. This work illustrates the need for a full characterisation of the toxicity of AsHCs in experimental animals to finally assess the risk to human health related to the presence of arsenolipids in seafood.}, language = {en} } @misc{NowakRussoSchlapbachetal.2015, author = {Nowak, Michael D. and Russo, Giancarlo and Schlapbach, Ralph and Huu, Cuong Nguyen and Lenhard, Michael and Conti, Elena}, title = {The draft genome of Primula veris yields insights into the molecular basis of heterostyly}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, number = {879}, issn = {1866-8372}, doi = {10.25932/publishup-43508}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435088}, pages = {19}, year = {2015}, abstract = {Background The flowering plant Primula veris is a common spring blooming perennial that is widely cultivated throughout Europe. This species is an established model system in the study of the genetics, evolution, and ecology of heterostylous floral polymorphisms. Despite the long history of research focused on this and related species, the continued development of this system has been restricted due the absence of genomic and transcriptomic resources. Results We present here a de novo draft genome assembly of P. veris covering 301.8 Mb, or approximately 63\% of the estimated 479.22 Mb genome, with an N50 contig size of 9.5 Kb, an N50 scaffold size of 164 Kb, and containing an estimated 19,507 genes. The results of a RADseq bulk segregant analysis allow for the confident identification of four genome scaffolds that are linked to the P. veris S-locus. RNAseq data from both P. veris and the closely related species P. vulgaris allow for the characterization of 113 candidate heterostyly genes that show significant floral morph-specific differential expression. One candidate gene of particular interest is a duplicated GLOBOSA homolog that may be unique to Primula (PveGLO2), and is completely silenced in L-morph flowers. Conclusions The P. veris genome represents the first genome assembled from a heterostylous species, and thus provides an immensely important resource for future studies focused on the evolution and genetic dissection of heterostyly. As the first genome assembled from the Primulaceae, the P. veris genome will also facilitate the expanded application of phylogenomic methods in this diverse family and the eudicots as a whole.}, language = {en} } @misc{MemczakLausterKaretal.2016, author = {Memczak, Henry and Lauster, Daniel and Kar, Parimal and Di Lella, Santiago and Volkmer, Rudolf and Knecht, Volker and Herrmann, Andreas and Ehrentreich-F{\"o}rster, Eva and Bier, Frank Fabian and St{\"o}cklein, Walter F. M.}, title = {Anti-hemagglutinin antibody derived lead peptides for inhibitors of influenza virus binding}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {536}, issn = {1866-8372}, doi = {10.25932/publishup-41087}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-410872}, pages = {24}, year = {2016}, abstract = {Antibodies against spike proteins of influenza are used as a tool for characterization of viruses and therapeutic approaches. However, development, production and quality control of antibodies is expensive and time consuming. To circumvent these difficulties, three peptides were derived from complementarity determining regions of an antibody heavy chain against influenza A spike glycoprotein. Their binding properties were studied experimentally, and by molecular dynamics simulations. Two peptide candidates showed binding to influenza A/Aichi/2/68 H3N2. One of them, termed PeB, with the highest affinity prevented binding to and infection of target cells in the micromolar region without any cytotoxic effect. PeB matches best the conserved receptor binding site of hemagglutinin. PeB bound also to other medical relevant influenza strains, such as human-pathogenic A/California/7/2009 H1N1, and avian-pathogenic A/MuteSwan/Rostock/R901/2006 H7N1. Strategies to improve the affinity and to adapt specificity are discussed and exemplified by a double amino acid substituted peptide, obtained by substitutional analysis. The peptides and their derivatives are of great potential for drug development as well as biosensing.}, language = {en} } @article{SelenkoBerkersCarteretal.2018, author = {Selenko, Eva and Berkers, Hannah and Carter, Angela and Woods, Stephen A. and Otto, Kathleen and Urbach, Tina and De Witte, Hans}, title = {On the dynamics of work identity in atypical employment}, series = {European journal of work and organizational psychology : the official journal of The European Association of Work and Organizational Psychology}, volume = {27}, journal = {European journal of work and organizational psychology : the official journal of The European Association of Work and Organizational Psychology}, number = {3}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {1359-432X}, doi = {10.1080/1359432X.2018.1444605}, pages = {324 -- 334}, year = {2018}, abstract = {Starting from the notion that work is an important part of who we are, we extend existing theory making on the interplay of work and identity by applying them to (so called) atypical work situations. Without the contextual stability of a permanent organizational position, the question "who one is" will be more difficult to answer. At the same time, a stable occupational identity might provide an even more important orientation to one's career attitudes and goals in atypical employment situations. So, although atypical employment might pose different challenges on identity, identity can still be a valid concept to assist the understanding of behaviour, attitudes, and well-being in these situations. Our analysis does not attempt to "reinvent" the concept of identity, but will elaborate how existing conceptualizations of identity as being a multiple (albeit perceived as singular), fluid (albeit perceived as stable), and actively forged (as well as passively influenced) construct that can be adapted to understand the effects of atypical employment contexts. Furthermore, we suggest three specific ways to understand the longitudinal dynamics of the interplay between atypical employment and identity over time: passive incremental, active incremental, and transformative change. We conclude with key learning points and outline a few practical recommendations for more research into identity as an explanatory mechanism for the effects of atypical employment situations.}, language = {en} } @phdthesis{Quade2018, author = {Quade, Markus}, title = {Symbolic regression for identification, prediction, and control of dynamical systems}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-419790}, school = {Universit{\"a}t Potsdam}, pages = {xiii, 134}, year = {2018}, abstract = {In the present work, we use symbolic regression for automated modeling of dynamical systems. Symbolic regression is a powerful and general method suitable for data-driven identification of mathematical expressions. In particular, the structure and parameters of those expressions are identified simultaneously. We consider two main variants of symbolic regression: sparse regression-based and genetic programming-based symbolic regression. Both are applied to identification, prediction and control of dynamical systems. We introduce a new methodology for the data-driven identification of nonlinear dynamics for systems undergoing abrupt changes. Building on a sparse regression algorithm derived earlier, the model after the change is defined as a minimum update with respect to a reference model of the system identified prior to the change. The technique is successfully exemplified on the chaotic Lorenz system and the van der Pol oscillator. Issues such as computational complexity, robustness against noise and requirements with respect to data volume are investigated. We show how symbolic regression can be used for time series prediction. Again, issues such as robustness against noise and convergence rate are investigated us- ing the harmonic oscillator as a toy problem. In combination with embedding, we demonstrate the prediction of a propagating front in coupled FitzHugh-Nagumo oscillators. Additionally, we show how we can enhance numerical weather predictions to commercially forecast power production of green energy power plants. We employ symbolic regression for synchronization control in coupled van der Pol oscillators. Different coupling topologies are investigated. We address issues such as plausibility and stability of the control laws found. The toolkit has been made open source and is used in turbulence control applications. Genetic programming based symbolic regression is very versatile and can be adapted to many optimization problems. The heuristic-based algorithm allows for cost efficient optimization of complex tasks. We emphasize the ability of symbolic regression to yield white-box models. In contrast to black-box models, such models are accessible and interpretable which allows the usage of established tool chains.}, language = {en} } @article{TrounsonBuschCollieretal.2020, author = {Trounson, Karl M. and Busch, Aglaja and Collier, Neil French and Robertson, Samuel}, title = {Effects of acute wearable resistance loading on overground running lower body kinematics}, series = {PLoS one}, volume = {15}, journal = {PLoS one}, number = {12}, publisher = {PLoS}, address = {San Francisco, California, US}, issn = {1932-6203}, doi = {10.1371/journal.pone.0244361}, pages = {19}, year = {2020}, abstract = {Field-based sports require athletes to run sub-maximally over significant distances, often while contending with dynamic perturbations to preferred coordination patterns. The ability to adapt movement to maintain performance under such perturbations appears to be trainable through exposure to task variability, which encourages movement variability. The aim of the present study was to investigate the extent to which various wearable resistance loading magnitudes alter coordination and induce movement variability during running. To investigate this, 14 participants (three female and 11 male) performed 10 sub-maximal velocity shuttle runs with either no weight, 1\%, 3\%, or 5\% of body weight attached to the lower limbs. Sagittal plane lower limb joint kinematics from one complete stride cycle in each run were assessed using functional data analysis techniques, both across the participant group and within-individuals. At the group-level, decreases in ankle plantarflexion following toe-off were evident in the 3\% and 5\% conditions, while increased knee flexion occurred during weight acceptance in the 5\% condition compared with unloaded running. At the individual-level, between-run joint angle profiles varied, with six participants exhibiting increased joint angle variability in one or more loading conditions compared with unloaded running. Loading of 5\% decreased between-run ankle joint variability among two individuals, likely in accordance with the need to manage increased system load or the novelty of the task. In terms of joint coordination, the most considerable alterations to coordination occurred in the 5\% loading condition at the hip-knee joint pair, however, only a minority of participants exhibited this tendency. Coaches should prescribe wearable resistance individually to perturb preferred coordination patterns and encourage movement variability without loading to the extent that movement options become limited.}, language = {en} }