@article{AgnePreickStraubeetal.2022,
author = {Agne, Stefanie and Preick, Michaela and Straube, Nicolas and Hofreiter, Michael},
title = {Simultaneous Barcode Sequencing of Diverse Museum Collection Specimens Using a Mixed RNA Bait Set},
series = {Frontiers in Ecology and Evolution},
volume = {10},
journal = {Frontiers in Ecology and Evolution},
publisher = {Frontiers Media S.A.},
address = {Lausanne, Schweiz},
issn = {2296-701X},
doi = {10.3389/fevo.2022.909846},
pages = {5},
year = {2022},
abstract = {A growing number of publications presenting results from sequencing natural history collection specimens reflect the importance of DNA sequence information from such samples. Ancient DNA extraction and library preparation methods in combination with target gene capture are a way of unlocking archival DNA, including from formalin-fixed wet-collection material. Here we report on an experiment, in which we used an RNA bait set containing baits from a wide taxonomic range of species for DNA hybridisation capture of nuclear and mitochondrial targets for analysing natural history collection specimens. The bait set used consists of 2,492 mitochondrial and 530 nuclear RNA baits and comprises specific barcode loci of diverse animal groups including both invertebrates and vertebrates. The baits allowed to capture DNA sequence information of target barcode loci from 84\% of the 37 samples tested, with nuclear markers being captured more frequently and consensus sequences of these being more complete compared to mitochondrial markers. Samples from dry material had a higher rate of success than wet-collection specimens, although target sequence information could be captured from 50\% of formalin-fixed samples. Our study illustrates how efforts to obtain barcode sequence information from natural history collection specimens may be combined and are a way of implementing barcoding inventories of scientific collection material.},
language = {en}
}
@article{BoekerHermanussenScheffler2022,
author = {Boeker, Sonja and Hermanussen, Michael and Scheffler, Christiane},
title = {Dental age is an independent marker of biological age},
series = {Human biology and public health},
volume = {2021},
journal = {Human biology and public health},
number = {3, Summer School Supplement},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph2021.3.24},
pages = {9},
year = {2022},
abstract = {Background: Biological age markers are a crucial indicator whether children are decelerated in growth tempo. Skeletal maturation is the standard measure. Yet, it relies on exposing children to x-radiation. Dental eruption is a potential, but highly debated, radiation free alternative. Objectives: We assess the interrelationship between dental eruption and other maturational markers. We hypothesize that dental age correlates with body height and skeletal age. We further evaluate how the three different variables behave in cohorts from differing social backgrounds. Sample and Method: Dental, skeletal and height data from the 1970s to 1990s from Guatemalan boys were converted into standard deviation scores, using external references for each measurement. The boys, aged between 7 and 12, derived from different social backgrounds (middle SES (N = 6529), low-middle SES (N = 736), low SES Ladino (N = 3653) and low SES Maya (N = 4587). Results: Dental age shows only a weak correlation with skeletal age (0.18) and height (0.2). The distinction between cohorts differs according to each of the three measurements. All cohorts differ significantly in height. In skeletal maturation, the middle SES cohort is significantly advanced compared to all other cohorts. The periodically malnourished cohorts of low SES Mayas and Ladinos are significantly delayed in dental maturation compared to the well-nourished low-middle and middle class Ladino children. Conclusion: Dental development is an independent system, that is regulated by different mechanisms than skeletal development and growth. Tooth eruption is sensitive to nutritional status, whereas skeletal age is more sensitive to socioeconomic background.},
language = {en}
}
@article{BormkiKnoescheSchneider2003,
author = {Bormki, G. and Kn{\"o}sche, Ralf and Schneider, Ingo},
title = {Untersuchungen zur N-Mineralisation und -Remobilisierung im Sediment eines extrem flachen Auensees (Schollener See)},
series = {Brandenburgische Umwelt-Berichte : BUB ; Schriftenreihe der Mathematisch-Naturwissenschaftlichen Fakult{\"a}t der Universit{\"a}t Potsdam},
volume = {13},
journal = {Brandenburgische Umwelt-Berichte : BUB ; Schriftenreihe der Mathematisch-Naturwissenschaftlichen Fakult{\"a}t der Universit{\"a}t Potsdam},
issn = {1434-2375},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-4081},
pages = {114 -- 120},
year = {2003},
language = {de}
}
@article{BornhorstAbdelilahSeyfried2021,
author = {Bornhorst, Dorothee and Abdelilah-Seyfried, Salim},
title = {Strong as a Hippo's Heart: Biomechanical Hippo Signaling During Zebrafish Cardiac Development},
series = {Frontiers in Cell and Developmental Biology},
volume = {9},
journal = {Frontiers in Cell and Developmental Biology},
publisher = {Frontiers Media},
address = {Lausanne, Schweiz},
issn = {2296-634X},
doi = {10.3389/fcell.2021.731101},
pages = {1 -- 10},
year = {2021},
abstract = {The heart is comprised of multiple tissues that contribute to its physiological functions. During development, the growth of myocardium and endocardium is coupled and morphogenetic processes within these separate tissue layers are integrated. Here, we discuss the roles of mechanosensitive Hippo signaling in growth and morphogenesis of the zebrafish heart. Hippo signaling is involved in defining numbers of cardiac progenitor cells derived from the secondary heart field, in restricting the growth of the epicardium, and in guiding trabeculation and outflow tract formation. Recent work also shows that myocardial chamber dimensions serve as a blueprint for Hippo signaling-dependent growth of the endocardium. Evidently, Hippo pathway components act at the crossroads of various signaling pathways involved in embryonic zebrafish heart development. Elucidating how biomechanical Hippo signaling guides heart morphogenesis has direct implications for our understanding of cardiac physiology and pathophysiology.},
language = {en}
}
@article{BurkartWichmannWattenbachetal.2003,
author = {Burkart, Michael and Wichmann, Matthias and Wattenbach, Martin and P{\"o}tsch, Joachim},
title = {Die Vegetation der unteren Havelaue},
series = {Brandenburgische Umwelt-Berichte : BUB ; Schriftenreihe der Mathematisch-Naturwissenschaftlichen Fakult{\"a}t der Universit{\"a}t Potsdam},
volume = {13},
journal = {Brandenburgische Umwelt-Berichte : BUB ; Schriftenreihe der Mathematisch-Naturwissenschaftlichen Fakult{\"a}t der Universit{\"a}t Potsdam},
issn = {1434-2375},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-4035},
pages = {53 -- 71},
year = {2003},
language = {de}
}
@misc{CleggWackerSpijkerman2021,
author = {Clegg, Mark R. and Wacker, Alexander and Spijkerman, Elly},
title = {Phenotypic Diversity and Plasticity of Photoresponse Across an Environmentally Contrasting Family of Phytoflagellates},
series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
number = {1219},
issn = {1866-8372},
doi = {10.25932/publishup-53617},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-536174},
year = {2021},
abstract = {Organisms often employ ecophysiological strategies to exploit environmental conditions and ensure bio-energetic success. However, the many complexities involved in the differential expression and flexibility of these strategies are rarely fully understood. Therefore, for the first time, using a three-part cross-disciplinary laboratory experimental analysis, we investigated the diversity and plasticity of photoresponsive traits employed by one family of environmentally contrasting, ecologically important phytoflagellates. The results demonstrated an extensive inter-species phenotypic diversity of behavioural, physiological, and compositional photoresponse across the Chlamydomonadaceae, and a multifaceted intra-species phenotypic plasticity, involving a broad range of beneficial photoacclimation strategies, often attributable to environmental predisposition and phylogenetic differentiation. Deceptively diverse and sophisticated strong (population and individual cell) behavioural photoresponses were observed, with divergence from a general preference for low light (and flexibility) dictated by intra-familial differences in typical habitat (salinity and trophy) and phylogeny. Notably, contrasting lower, narrow, and flexible compared with higher, broad, and stable preferences were observed in freshwater vs. brackish and marine species. Complex diversity and plasticity in physiological and compositional photoresponses were also discovered. Metabolic characteristics (such as growth rates, respiratory costs and photosynthetic capacity, efficiency, compensation and saturation points) varied elaborately with species, typical habitat (often varying more in eutrophic species, such as Chlamydomonas reinhardtii), and culture irradiance (adjusting to optimise energy acquisition and suggesting some propensity for low light). Considerable variations in intracellular pigment and biochemical composition were also recorded. Photosynthetic and accessory pigments (such as chlorophyll a, xanthophyll-cycle components, chlorophyll a:b and chlorophyll a:carotenoid ratios, fatty acid content and saturation ratios) varied with phylogeny and typical habitat (to attune photosystem ratios in different trophic conditions and to optimise shade adaptation, photoprotection, and thylakoid architecture, particularly in freshwater environments), and changed with irradiance (as reaction and harvesting centres adjusted to modulate absorption and quantum yield). The complex, concomitant nature of the results also advocated an integrative approach in future investigations. Overall, these nuanced, diverse, and flexible photoresponsive traits will greatly contribute to the functional ecology of these organisms, addressing environmental heterogeneity and potentially shaping individual fitness, spatial and temporal distribution, prevalence, and ecosystem dynamics.},
language = {en}
}
@article{CleggWackerSpijkerman2021,
author = {Clegg, Mark R. and Wacker, Alexander and Spijkerman, Elly},
title = {Phenotypic Diversity and Plasticity of Photoresponse Across an Environmentally Contrasting Family of Phytoflagellates},
series = {Frontiers in plant science : FPLS},
journal = {Frontiers in plant science : FPLS},
number = {12},
publisher = {Frontiers Media},
address = {Lausanne},
issn = {1664-462X},
doi = {10.3389/fpls.2021.707541},
year = {2021},
abstract = {Organisms often employ ecophysiological strategies to exploit environmental conditions and ensure bio-energetic success. However, the many complexities involved in the differential expression and flexibility of these strategies are rarely fully understood. Therefore, for the first time, using a three-part cross-disciplinary laboratory experimental analysis, we investigated the diversity and plasticity of photoresponsive traits employed by one family of environmentally contrasting, ecologically important phytoflagellates. The results demonstrated an extensive inter-species phenotypic diversity of behavioural, physiological, and compositional photoresponse across the Chlamydomonadaceae, and a multifaceted intra-species phenotypic plasticity, involving a broad range of beneficial photoacclimation strategies, often attributable to environmental predisposition and phylogenetic differentiation. Deceptively diverse and sophisticated strong (population and individual cell) behavioural photoresponses were observed, with divergence from a general preference for low light (and flexibility) dictated by intra-familial differences in typical habitat (salinity and trophy) and phylogeny. Notably, contrasting lower, narrow, and flexible compared with higher, broad, and stable preferences were observed in freshwater vs. brackish and marine species. Complex diversity and plasticity in physiological and compositional photoresponses were also discovered. Metabolic characteristics (such as growth rates, respiratory costs and photosynthetic capacity, efficiency, compensation and saturation points) varied elaborately with species, typical habitat (often varying more in eutrophic species, such as Chlamydomonas reinhardtii), and culture irradiance (adjusting to optimise energy acquisition and suggesting some propensity for low light). Considerable variations in intracellular pigment and biochemical composition were also recorded. Photosynthetic and accessory pigments (such as chlorophyll a, xanthophyll-cycle components, chlorophyll a:b and chlorophyll a:carotenoid ratios, fatty acid content and saturation ratios) varied with phylogeny and typical habitat (to attune photosystem ratios in different trophic conditions and to optimise shade adaptation, photoprotection, and thylakoid architecture, particularly in freshwater environments), and changed with irradiance (as reaction and harvesting centres adjusted to modulate absorption and quantum yield). The complex, concomitant nature of the results also advocated an integrative approach in future investigations. Overall, these nuanced, diverse, and flexible photoresponsive traits will greatly contribute to the functional ecology of these organisms, addressing environmental heterogeneity and potentially shaping individual fitness, spatial and temporal distribution, prevalence, and ecosystem dynamics.},
language = {en}
}
@article{CzarneckaWeicheltRoedigeretal.2022,
author = {Czarnecka, Malgorzata and Weichelt, Ulrike and R{\"o}diger, Stefan and Hanack, Katja},
title = {Novel Anti Double-Stranded Nucleic Acids Full-Length Recombinant Camelid Heavy-Chain Antibody for the Detection of miRNA},
series = {International Journal of Molecular Sciences},
volume = {23},
journal = {International Journal of Molecular Sciences},
edition = {11},
publisher = {MDPI},
address = {Basel, Schweiz},
issn = {1422-0067},
doi = {10.3390/ijms23116275},
pages = {1 -- 18},
year = {2022},
abstract = {The discovery that certain diseases have specific miRNA signatures which correspond to disease progression opens a new biomarker category. The detection of these small non-coding RNAs is performed routinely using body fluids or tissues with real-time PCR, next-generation sequencing, or amplification-based miRNA assays. Antibody-based detection systems allow an easy onset handling compared to PCR or sequencing and can be considered as alternative methods to support miRNA diagnostic in the future. In this study, we describe the generation of a camelid heavy-chain-only antibody specifically recognizing miRNAs to establish an antibody-based detection method. The generation of nucleic acid-specific binders is a challenge. We selected camelid binders via phage display, expressed them as VHH as well as full-length antibodies, and characterized the binding to several miRNAs from a signature specific for dilated cardiomyopathy. The described workflow can be used to create miRNA-specific binders and establish antibody-based detection methods to provide an additional way to analyze disease-specific miRNA signatures.},
language = {en}
}
@article{EccardHerdeSchusteretal.2022,
author = {Eccard, Jana and Herde, Antje and Schuster, Andrea C. and Liesenjohann, Thilo and Knopp, Tatjana and Heckel, Gerald and Dammhahn, Melanie},
title = {Fitness, risk taking, and spatial behavior covary with boldness in experimental vole populations},
series = {Ecology And Evolution},
journal = {Ecology And Evolution},
publisher = {John Wiley \& Sons, Inc.},
address = {Vereinigte Staaten},
issn = {2045-7758},
doi = {10.1002/ece3.8521},
pages = {1 -- 15},
year = {2022},
abstract = {Individuals of a population may vary along a pace-of-life syndrome from highly fecund, short-lived, bold, dispersive "fast" types at one end of the spectrum to less fecund, long-lived, shy, plastic "slow" types at the other end. Risk-taking behavior might mediate the underlying life history trade-off, but empirical evidence supporting this hypothesis is still ambiguous. Using experimentally created populations of common voles (Microtus arvalis)—a species with distinct seasonal life history trajectories—we aimed to test whether individual differences in boldness behavior covary with risk taking, space use, and fitness. We quantified risk taking, space use (via automated tracking), survival, and reproductive success (via genetic parentage analysis) in 8 to 14 experimental, mixed-sex populations of 113 common voles of known boldness type in large grassland enclosures over a significant part of their adult life span and two reproductive events. Populations were assorted to contain extreme boldness types (bold or shy) of both sexes. Bolder individuals took more risks than shyer ones, which did not affect survival. Bolder males but not females produced more offspring than shy conspecifics. Daily home range and core area sizes, based on 95\% and 50\% Kernel density estimates (20 ± 10 per individual, n = 54 individuals), were highly repeatable over time. Individual space use unfolded differently for sex-boldness type combinations over the course of the experiment. While day ranges decreased for shy females, they increased for bold females and all males. Space use trajectories may, hence, indicate differences in coping styles when confronted with a novel social and physical environment. Thus, interindividual differences in boldness predict risk taking under near-natural conditions and have consequences for fitness in males, which have a higher reproductive potential than females. Given extreme inter- and intra-annual fluctuations in population density in the study species and its short life span, density-dependent fluctuating selection operating differently on the sexes might maintain (co)variation in boldness, risk taking, and pace-of-life.},
language = {en}
}
@article{EckertHerdenStiftetal.2022,
author = {Eckert, Silvia and Herden, Jasmin and Stift, Marc and Durka, Walter and Kleunen, Mark van and Joshi, Jasmin},
title = {Traces of genetic but not epigenetic adaptation in the invasive goldenrod Solidago canadensis despite the absence of population structure},
series = {Frontiers in Ecology and Evolution},
volume = {10},
journal = {Frontiers in Ecology and Evolution},
publisher = {Frontiers},
address = {Lausanne, Schweiz},
issn = {2296-701X},
doi = {10.3389/fevo.2022.856453},
pages = {1 -- 17},
year = {2022},
abstract = {Biological invasions may result from multiple introductions, which might compensate for reduced gene pools caused by bottleneck events, but could also dilute adaptive processes. A previous common-garden experiment showed heritable latitudinal clines in fitness-related traits in the invasive goldenrod Solidago canadensis in Central Europe. These latitudinal clines remained stable even in plants chemically treated with zebularine to reduce epigenetic variation. However, despite the heritability of traits investigated, genetic isolation-by-distance was non-significant. Utilizing the same specimens, we applied a molecular analysis of (epi)genetic differentiation with standard and methylation-sensitive (MSAP) AFLPs. We tested whether this variation was spatially structured among populations and whether zebularine had altered epigenetic variation. Additionally, we used genome scans to mine for putative outlier loci susceptible to selection processes in the invaded range. Despite the absence of isolation-by-distance, we found spatial genetic neighborhoods among populations and two AFLP clusters differentiating northern and southern Solidago populations. Genetic and epigenetic diversity were significantly correlated, but not linked to phenotypic variation. Hence, no spatial epigenetic patterns were detected along the latitudinal gradient sampled. Applying genome-scan approaches (BAYESCAN, BAYESCENV, RDA, and LFMM), we found 51 genetic and epigenetic loci putatively responding to selection. One of these genetic loci was significantly more frequent in populations at the northern range. Also, one epigenetic locus was more frequent in populations in the southern range, but this pattern was lost under zebularine treatment. Our results point to some genetic, but not epigenetic adaptation processes along a large-scale latitudinal gradient of S. canadensis in its invasive range.},
language = {en}
}
@phdthesis{Fritz2006,
author = {Fritz, Christina},
title = {Der Einfluß des prim{\"a}ren Stickstoffstoffwechsels auf den Aminos{\"a}ure- und Sekund{\"a}rstoffwechsel in Nicotiana tabacum L.},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13322},
school = {Universit{\"a}t Potsdam},
year = {2006},
abstract = {Es ist bekannt, dass {\"A}nderungen im Kohlenstoff- bzw. Stickstoffstaus der Pflanzen zu einer parallelen statt reziproken {\"A}nderung der kohlenstoff- und stickstoffhaltigen Prim{\"a}rmetabolite f{\"u}hren. Unter diesem Gesichtspunkt wurden in der vorliegenden Arbeit der Aminos{\"a}urestoffwechsel und der Sekund{\"a}rstoffwechsel unter reduzierten Stickstoffbedingungen untersucht. Zur Beeinflussung des Stickstoffstoffwechsels wurden nitratmangelern{\"a}hrte Tabakwildtyppflanzen und Genotypen mit unterschiedlich stark reduzierter Nitratreduktase-Aktivit{\"a}t verwendet. Dieses experimentelle System erlaubt zus{\"a}tzlich durch den Vergleich Nitrat defizienter Wildtyppflanzen mit Nitrat akkumulierenden NIA-Transformanten Prozesse zu identifizieren, die durch Nitrat gesteuert werden. Die Analysen der Prim{\"a}r- und Sekund{\"a}rmetabolite wurde in allen Genotypen diurnal durchgef{\"u}hrt, um auch tageszeitlich abh{\"a}ngige Prozesse zu identifizieren. Die Analyse der absoluten Gehalte aller individuellen Aminos{\"a}uren enth{\"u}llte bei den meisten erstaunlich stabile diurnale Muster mit einem Anstieg w{\"a}hrend des Tages und einem Abfall in der Nacht in Wildtyppflanzen gewachsen mit ausreichend Nitrat. Dieses Ergebnis legt die Schlussfolgerung nahe, dass die Biosynthese der Aminos{\"a}uren koordiniert abl{\"a}uft. In Pflanzen mit reduziertem Stickstoffstatus haben diese diurnalen Muster jedoch keinen Bestand. Die Kombination des erzeugten stickstoffbasierten Aminos{\"a}uredatensatz in Kombination mit einem bereits erzeugten Aminos{\"a}uredatensatz unter kohlenstofflimitierten Bedingungen von Matt et al. (2002) f{\"u}hrte durch Hauptkomponentenanalyse (PCA) und Korrelationsanalyse zu dem Ergebnis, dass die Hypothese nach einer koordinierten Aminos{\"a}urebiosynthese nicht allgemeine G{\"u}ltigkeit hat. Die PCA identifizierte Glutamin, Glutamat, Aspartat, Glycin, Pheny-lalanin und Threonin als Faktoren, die den Datens{\"a}tzen ihre charakteristische Eigenschaft und deren Varianz verleihen. Die Korrelationsanalyse zeigte, dass die sehr guten Korrelationen der individuellen Aminos{\"a}uren untereinander in reduzierten Stickstoff- und Kohlenstoffbedingungen sich verschlechtern. Das Verh{\"a}ltnis einer einzelnen Aminos{\"a}ure relativ zu den anderen f{\"u}hrte zur Identifizierung einiger Aminos{\"a}uren, die individuelle Antworten auf Stickstoff- und/oder Kohlenstoffstatus zeigen, und/oder speziell auf Nitrat, Licht und/oder den E-nergiestatus der Thylakoidmembran. Glutamat beispielsweise verh{\"a}lt sich in den meisten Situationen stabil, Phenylalanin dagegen zeigt in jeder physiologischen Situation eine individuelle Antwort. Die Ergebnisse dieser Arbeit f{\"u}hren zu einer Erweiterung der Hypothese einer koordinierten Synthese der Aminos{\"a}uren dahingehend, dass diese nicht generell f{\"u}r alle Aminos{\"a}uren angenommen werden kann. Es gibt einige Aminos{\"a}uren deren, Anteile sich situationsbedingt anpassen. Die Reduktion des Stickstoffstatus in nitratmangelern{\"a}hrten Tabakwildtyppflanzen f{\"u}hrte zu der, nach der „Carbon-Nutrient-Balance" Hypothese erwarteten Verlagerung der kohlenstoffreichen Phenylpropanoide und des stickstoffreichen Nikotins. Die Erh{\"o}hung der Phenylpropanoidgehalte war nicht in der Nitrat akkumulierenden NIA-Transformante zu beobachten und somit konnte Nitrat als regulatorisches Element identifiziert werden. Ein Einfluss der Vorl{\"a}ufermetabolite konnte ausgeschlossen werden, da sowohl nitratmangelern{\"a}hrter Wildtyp als auch die Nitrat akkumulierende NIA-Transformante {\"a}hnliche Gehalte dieser aufwiesen. Genexpressionsanalysen {\"u}ber Mikroarray-Hybridisierung und quantitative RT-PCR zeigten, dass Nitrat durch noch nicht gekl{\"a}rte Mechanismen Einfluss auf die Expression einiger Gene nimmt, die dem Phenylpropanoidstoffwechsels zugeordnet sind. Aus der Arbeit hervorgegangene Ver{\"o}ffentlichungen: Christina Fritz, Natalia Palacios-Rojas, Regina Feil und Mark Stitt (2006) Regulation of Secondary Metabolism by the Carbon-Nitrogen Status in Tobacco: Nitrate Inhibits Large Sectors of Phenylpropanoid Metabolism. Plant Journal 46, 533 - 548 Christina Fritz, Petra Matt, Cathrin M{\"u}ller, Regina Feil und Mark Stitt (2006) Impact of the Carbon-Nitrogen Status on the Amino Acid Profile in Tobacco Source Leaves. Plant, Cell and Environment 29 (11), 2009 - 2111},
language = {de}
}
@article{GambaJonesTeasdaleetal.2014,
author = {Gamba, Cristina and Jones, Eppie R. and Teasdale, Matthew D. and McLaughlin, Russell L. and Gonz{\´a}lez-Fortes, Gloria M. and Mattiangeli, Valeria and Domboroczki, Laszlo and Kovari, Ivett and Pap, Ildiko and Anders, Alexandra and Whittle, Alasdair and Dani, Janos and Raczky, Pal and Higham, Thomas F. G. and Hofreiter, Michael and Bradley, Daniel G. and Pinhasi, Ron},
title = {Genome flux and stasis in a five millennium transect of European prehistory},
series = {Nature Communications},
volume = {5},
journal = {Nature Communications},
publisher = {Nature Publ. Group},
address = {London},
issn = {2041-1723},
doi = {10.1038/ncomms6257},
pages = {9},
year = {2014},
abstract = {The Great Hungarian Plain was a crossroads of cultural transformations that have shaped European prehistory. Here we analyse a 5,000-year transect of human genomes, sampled from petrous bones giving consistently excellent endogenous DNA yields, from 13 Hungarian Neolithic, Copper, Bronze and Iron Age burials including two to high (similar to 22x) and seven to similar to 1x coverage, to investigate the impact of these on Europe's genetic landscape. These data suggest genomic shifts with the advent of the Neolithic, Bronze and Iron Ages, with interleaved periods of genome stability. The earliest Neolithic context genome shows a European hunter-gatherer genetic signature and a restricted ancestral population size, suggesting direct contact between cultures after the arrival of the first farmers into Europe. The latest, Iron Age, sample reveals an eastern genomic influence concordant with introduced Steppe burial rites. We observe transition towards lighter pigmentation and surprisingly, no Neolithic presence of lactase persistence.},
language = {en}
}
@article{GasparatosSchefflerHermanussen2023,
author = {Gasparatos, Nikolaos and Scheffler, Christiane and Hermanussen, Michael},
title = {Assessing the applicability of changepoint analysis to analyse short-term growth},
series = {Human biology and public health},
volume = {1},
journal = {Human biology and public health},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph2023.1.62},
pages = {15},
year = {2023},
abstract = {Background: Assessing short-term growth in humans is still fraught with difficulties. Especially when looking for small variations and increments, such as mini growth spurts, high precision instruments or frequent measurements are necessary. Daily measurements however require a lot of effort, both for anthropologists and for the subjects. Therefore, new sophisticated approaches are needed that reduce fluctuations and reveal underlying patterns. Objectives: Changepoints are abrupt variations in the properties of time series data. In the context of growth, such variations could be variation in mean height. By adjusting the variance and using different growth models, we assessed the ability of changepoint analysis to analyse short-term growth and detect mini growth spurts. Sample and Methods: We performed Bayesian changepoint analysis on simulated growth data using the bcp package in R. Simulated growth patterns included stasis, linear growth, catch-up growth, and mini growth spurts. Specificity and a normalised variant of the Matthews correlation coefficient (MCC) were used to assess the algorithm's performance. Welch's t-test was used to compare differences of the mean. Results: First results show that changepoint analysis can detect mini growth spurts. However, the ability to detect mini growth spurts is highly dependent on measurement error. Data preparation, such as ranking and rotating time series data, showed negligible improvements. Missing data was an issue and may affect the prediction quality of the classification metrics. Conclusion: Changepoint analysis is a promising tool to analyse short-term growth. However, further optimisation and analysis of real growth data is needed to make broader generalisations.},
language = {en}
}
@article{GlowinskiAutenrieth2023,
author = {Glowinski, Ingrid and Autenrieth, Marijke},
title = {Eigene Forschung im Labor, um naturwissenschaftliche Erkenntnisgewinnung kompetent unterrichten zu k{\"o}nnen?},
series = {PSI-Potsdam: Ergebnisbericht zu den Aktivit{\"a}ten im Rahmen der Qualit{\"a}tsoffensive Lehrerbildung (2019-2023) (Potsdamer Beitr{\"a}ge zur Lehrerbildung und Bildungsforschung ; 3)},
journal = {PSI-Potsdam: Ergebnisbericht zu den Aktivit{\"a}ten im Rahmen der Qualit{\"a}tsoffensive Lehrerbildung (2019-2023) (Potsdamer Beitr{\"a}ge zur Lehrerbildung und Bildungsforschung ; 3)},
number = {3},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
isbn = {978-3-86956-568-2},
issn = {2626-3556},
doi = {10.25932/publishup-61792},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-617922},
pages = {273 -- 293},
year = {2023},
abstract = {Im Rahmen des PSI-Projekts wurde eine Lehrveranstaltung konzipiert, die Lehramtsstudierenden einen vertieften Einblick sowohl in den Ablauf von Forschung als auch eine Bearbeitung einer eigenen experimentellen Forschungsaufgabe erm{\"o}glichen soll. Anlass waren die Ber{\"u}cksichtigung eines „Wissens {\"u}ber Erkenntnisgewinnung in der Disziplin" im Modell des „Erweiterten Fachwissens f{\"u}r den schulischen Kontext" (PSI) sowie Erkenntnisse empirischer Studien, die die Relevanz eigener Forschungserfahrung f{\"u}r das Unterrichten naturwissenschaftlicher Erkenntnisgewinnungsprozesse zeigen. Hier stellen wir eine neue Lehrveranstaltung (4 SWS) vor, die den angehenden Lehrkr{\"a}ften Forschungserfahrung erm{\"o}glicht (Seminar und Praktikum). Die Lehrveranstaltung vermittelt Einblicke in Forschung und die „Natur der Naturwissenschaften", erm{\"o}glicht das Durchf{\"u}hren eigener wissenschaftlicher und schulrelevanter Experimente und bietet eine angemessene Reflexion {\"u}ber die verschiedenen Kurselemente. Die Evaluationsergebnisse sind {\"u}berwiegend positiv, zeigen aber auch, dass f{\"u}r die Studierenden die wahrgenommene Schulrelevanz und die fachdidaktischen Aspekte ein wichtiges Kriterium f{\"u}r die positive Bewertung sind.},
language = {de}
}
@article{GrothSchefflerHermanussen2023,
author = {Groth, Detlef and Scheffler, Christiane and Hermanussen, Michael},
title = {Human growth data analysis and statistics - the 5th G{\"u}lpe International Student Summer School},
series = {Human biology and public health},
volume = {1},
journal = {Human biology and public health},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph2023.1.70},
pages = {5},
year = {2023},
abstract = {The Summer School in G{\"u}lpe (Ecological Station of the University of Potsdam) offers an exceptional learning opportunity for students to apply their knowledge and skills to real-world problems. With the guidance of experienced human biologists, statisticians, and programmers, students have the unique chance to analyze their own data and gain valuable insights. This interdisciplinary setting not only bridges different research areas but also leads to highly valuable outputs. The progress of students within just a few days is truly remarkable, especially when they are motivated and receive immediate feedback on their questions, problems, and results. The Summer School covers a wide range of topics, with this year's focus mainly on two areas: understanding the impact of socioeconomic and physiological factors on human development and mastering statistical techniques for analyzing data such as changepoint analysis and the St. Nicolas House Analysis (SNHA) to visualize interacting variables. The latter technique, born out of the Summer School's emphasis on gaining comprehensive data insights and understanding major relationships, has proven to be a valuable tool for researchers in the field. The articles in this special issue demonstrate that the Summer School in G{\"u}lpe stands as a testament to the power of practical learning and collaboration. Students who attend not only gain hands-on experience but also benefit from the expertise of professionals and the opportunity to engage with peers from diverse disciplines.},
language = {en}
}
@article{HeringHauptfleischJagoetal.2022,
author = {Hering, Robert and Hauptfleisch, Morgan and Jago, Mark and Smith, Taylor and Kramer-Schadt, Stephanie and Stiegler, Jonas and Blaum, Niels},
title = {Don't stop me now: Managed fence gaps could allow migratory ungulates to track dynamic resources and reduce fence related energy loss},
series = {Frontiers in Ecology and Evolution},
journal = {Frontiers in Ecology and Evolution},
publisher = {Frontiers},
address = {Lausanne, Schweiz},
issn = {2296-701X},
doi = {10.3389/fevo.2022.907079},
pages = {1 -- 18},
year = {2022},
abstract = {In semi-arid environments characterized by erratic rainfall and scattered primary production, migratory movements are a key survival strategy of large herbivores to track resources over vast areas. Veterinary Cordon Fences (VCFs), intended to reduce wildlife-livestock disease transmission, fragment large parts of southern Africa and have limited the movements of large wild mammals for over 60 years. Consequently, wildlife-fence interactions are frequent and often result in perforations of the fence, mainly caused by elephants. Yet, we lack knowledge about at which times fences act as barriers, how fences directly alter the energy expenditure of native herbivores, and what the consequences of impermeability are. We studied 2-year ungulate movements in three common antelopes (springbok, kudu, eland) across a perforated part of Namibia's VCF separating a wildlife reserve and Etosha National Park using GPS telemetry, accelerometer measurements, and satellite imagery. We identified 2905 fence interaction events which we used to evaluate critical times of encounters and direct fence effects on energy expenditure. Using vegetation type-specific greenness dynamics, we quantified what animals gained in terms of high quality food resources from crossing the VCF. Our results show that the perforation of the VCF sustains herbivore-vegetation interactions in the savanna with its scattered resources. Fence permeability led to peaks in crossing numbers during the first flush of woody plants before the rain started. Kudu and eland often showed increased energy expenditure when crossing the fence. Energy expenditure was lowered during the frequent interactions of ungulates standing at the fence. We found no alteration of energy expenditure when springbok immediately found and crossed fence breaches. Our results indicate that constantly open gaps did not affect energy expenditure, while gaps with obstacles increased motion. Closing gaps may have confused ungulates and modified their intended movements. While browsing, sedentary kudu's use of space was less affected by the VCF; migratory, mixed-feeding springbok, and eland benefited from gaps by gaining forage quality and quantity after crossing. This highlights the importance of access to vast areas to allow ungulates to track vital vegetation patches.},
language = {en}
}
@article{HermanussenGrothScheffler2022,
author = {Hermanussen, Michael and Groth, Detlef and Scheffler, Christiane},
title = {Human growth data analyses and statistics},
series = {Human biology and public health},
volume = {2021},
journal = {Human biology and public health},
number = {3, Summer School Supplement},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph2021.3.29},
pages = {4},
year = {2022},
abstract = {Students learn by repetition. Repetition is essential, but repetition needs questioning, and questioning the repertoire belongs to the essential tasks of student education. Guiding students to questioning was and is our prime motive to offer our International Student Summer Schools. The data were critically discussed among the students, in the twilight of Just So Stories, common knowledge, and prompted questioning of contemporary solutions. For these schools, the students bring their own data, carry their preliminary concepts, and in group discussions, they may have to challenge these concepts. Catch-up growth is known to affect long bone growth, but different opinions exist to what extent it also affects body proportions. Skeletal age and dental development are considered appropriate measures of maturation, but it appears that both system develop independently and are regulated by different mechanisms. Body weight distributions are assumed to be skewed, yet, historic data disproved this assumption. Many discussions focused on current ideas of global growth standards as a common yardstick for all populations world-wide, with new statistical tools being developed including network reconstruction and evaluation of the reconstructs to determine the confidence of graph prediction methods.},
language = {en}
}
@article{HermanussenScheffler2023,
author = {Hermanussen, Michael and Scheffler, Christiane},
title = {Nutrition, size, and tempo},
series = {Human biology and public health},
volume = {2022},
journal = {Human biology and public health},
number = {3},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph2022.3.37},
pages = {11},
year = {2023},
abstract = {Nutrition is a prerequisite, but not a regulator of growth. Growth is defined as increase in size over time. The understanding of growth includes an understanding of the binary concept of physical time and individual tempo. Excess food causes tempo acceleration. Food restriction delays tempo. Tempo reflects the pace of life. It is a dynamic physical response to a broad spectrum of social, economic, political, and emotional (SEPE) factors and can affect life expectancy. Variations in tempo create distortions of the z-score patterns of height and weight. Illness or intermediate food shortage lead to intermediate halts in development and create short dips in the z-score patterns. Children who develop throughout life at delayed pace usually run at lower z-scores for height and weight, and show a characteristic adolescent trough; children who develop throughout life at faster than average pace usually run at higher z-scores and show a characteristic adolescent peak in their z-score patterns. During adolescence, almost half of the height variance is due to tempo variation. There is not one tempo for the whole body. Different organ systems grow and mature at different pace.},
language = {en}
}
@article{HermanussenScheffler2022,
author = {Hermanussen, Michael and Scheffler, Christiane},
title = {Evidence of chronic undernutrition in late 19th century German infants of all social classes},
series = {Human biology and public health},
volume = {2022},
journal = {Human biology and public health},
number = {2},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph2022.2.42},
pages = {9},
year = {2022},
abstract = {125 years ago, European infants grew differently from modern infants. We show weight gains of 20 healthy children weighed longitudinally from birth to age 1 year, published by Camerer in 1882. The data illustrate the historically prevalent concepts of infant nutrition practiced by German civil servants, lawyers, merchants, university professors, physicians, foresters and farmers. Breastfeeding by the mother was not truly appreciated in those days; children were often breastfed by wet nurses or received bottled milk. Bottle feeding mainly used diluted cow's milk with some added carbohydrates, without evidence that appropriate amounts of oil, butter or other fatty components were added. French children from 1914 showed similar weight gain patterns suggesting similar feeding practices. The historical data suggest that energy deficient infant formula was fed regularly in the late 19th and early 20th century Europe, regardless of wealth and social class. The data question current concerns that temporarily feeding energy deficient infant formula may warrant serious anxieties regarding long-term cognitive, social and emotional behavioral development.},
language = {en}
}
@article{HermanussenSchefflerPulunganetal.2023,
author = {Hermanussen, Michael and Scheffler, Christiane and Pulungan, Aman B. and Bandyopadhyay, Arup Ratan and Ghosh, Jyoti Ratan and {\"O}zdemir, Ay{\c{s}}eg{\"u}l and Koca {\"O}zer, Ba{\c{s}}ak and Musalek, Martin and Lebedeva, Lidia and Godina, Elena and Bogin, Barry and Tutkuviene, Janina and Budrytė, Milda and Gervickaite, Simona and Limony, Yehuda and Kirchengast, Sylvia and Buston, Peter and Groth, Detlef and R{\"o}sler, Antonia and Gasparatos, Nikolaos and Erofeev, Sergei and Novine, Masiar and Navazo, B{\´a}rbara and Dahinten, Silvia and Gomuła, Aleksandra and Nowak-Szczepańska, Natalia and Kozieł, Sławomir},
title = {Environment, social behavior, and growth},
series = {Human biology and public health},
volume = {1},
journal = {Human biology and public health},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph2023.1.59},
pages = {14},
year = {2023},
abstract = {Twenty-four scientists met for the annual Auxological conference held at Krobielowice castle, Poland, to discuss the diverse influences of the environment and of social behavior on growth following last year's focus on growth and public health concerns (Hermanussen et al., 2022b). Growth and final body size exhibit marked plastic responses to ecological conditions. Among the shortest are the pygmoid people of Rampasasa, Flores, Indonesia, who still live under most secluded insular conditions. Genetics and nutrition are usually considered responsible for the poor growth in many parts of this world, but evidence is accumulating on the prominent impact of social embedding on child growth. Secular trends not only in the growth of height, but also in body proportions, accompany the secular changes in the social, economic and political conditions, with major influences on the emotional and educational circumstances under which the children grow up (Bogin, 2021). Aspects of developmental tempo and aspects of sports were discussed, and the impact of migration by the example of women from Bangladesh who grew up in the UK. Child growth was considered in particular from the point of view of strategic adjustments of individual size within the network of its social group. Theoretical considerations on network characteristics were presented and related to the evolutionary conservation of growth regulating hypothalamic neuropeptides that have been shown to link behavior and physical growth in the vertebrate species. New statistical approaches were presented for the evaluation of short term growth measurements that permit monitoring child growth at intervals of a few days and weeks.},
language = {en}
}
@phdthesis{Hoffmann2007,
author = {Hoffmann, Toni},
title = {Cloning and characterisation of the HMA3 gene and its promoter from Arabidopsis halleri (L.) O'Kane and Al'Shehbaz and Arabidopsis thaliana (L.) Heynhold},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15259},
school = {Universit{\"a}t Potsdam},
year = {2007},
abstract = {Being living systems unable to adjust their location to changing environmental conditions, plants display homeostatic networks that have evolved to maintain transition metal levels in a very narrow concentration range in order to avoid either deficiency or toxicity. Hence, plants possess a broad repertoire of mechanisms for the cellular uptake, compartmentation and efflux, as well as for the chelation of transition metal ions. A small number of plants are hypertolerant to one or a few specific transition metals. Some metal tolerant plants are also able to hyperaccumulate metal ions. The Brassicaceae family member Arabidopis halleri ssp. halleri (L.) O´KANE and AL´SHEHBAZ is a hyperaccumulator of zinc (Zn), and it is closely related to the non-hypertolerant and non-hyperaccumulating model plant Arabidopsis thaliana (L.) HEYNHOLD. The close relationship renders A. halleri a promising emerging model plant for the comparative investigation of the molecular mechanisms behind hypertolerance and hyperaccumulation. Among several potential candidate genes that are probably involved in mediating the zinc-hypertolerant and zinc-hyperaccumulating trait is AhHMA3. The AhHMA3 gene is highly similar to AtHMA3 (AGI number: At4g30120) in A. thaliana, and its encoded protein belongs to the P-type IB ATPase family of integral membrane transporter proteins that transport transition metals. In contrast to the low AtHMA3 transcript levels in A. thaliana, the gene was found to be constitutively highly expressed across different Zn treatments in A. halleri, especially in shoots. In this study, the cloning and characterisation of the HMA3 gene and its promoter from Arabidopsis halleri (L.) O´KANE and AL´SHEHBAZ and Arabidopsis thaliana (L.) HEYNHOLD is described. Heterologously expressed AhHMA3 mediated enhanced tolerance to Zn and to a much lesser degree to cadmium (Cd) but not to cobalt (Co) in metal-sensitive mutant strains of budding yeast. It is demonstrated that the genome of A. halleri contains at least four copies of AhHMA3, AhHMA3-1 to AhHMA3-4. A copy-specific real-time RT-PCR indicated that an AhHMA3-1 related gene copy is the source of the constitutively high transcript level in A. halleri and not a gene copy similar to AhHMA3-2 or AhHMA3-4. In accordance with the enhanced AtHMA3mRNA transcript level in A. thaliana roots, an AtHMA3 promoter-GUS gene construct mediated GUS activity predominantly in the vascular tissues of roots and not in shoots. However, the observed AhHMA3-1 and AhHMA3-2 promoter-mediated GUS activity in A. thaliana or A. halleri plants did not reflect the constitutively high expression of AhHMA3 in shoots of A. halleri. It is suggested that other factors e. g. characteristic sequence inserts within the first intron of AhHMA3-1 might enable a constitutively high expression. Moreover, the unknown promoter of the AhHMA3-3 gene copy could be the source of the constitutively high AhHMA3 transcript levels in A. halleri. In that case, the AhHMA3-3 sequence is predicted to be highly homologous to AhHMA3-1. The lack of solid localisation data for the AhHMA3 protein prevents a clear functional assignment. The provided data suggest several possible functions of the AhHMA3 protein: Like AtHMA2 and AtHMA4 it might be localised to the plasma membrane and could contribute to the efficient translocation of Zn from root to shoot and/or to the cell-to-cell distribution of Zn in the shoot. If localised to the vacuolar membrane, then a role in maintaining a low cytoplasmic zinc concentration by vacuolar zinc sequestration is possible. In addition, AhHMA3 might be involved in the delivery of zinc ions to trichomes and mesophyll leaf cells that are major zinc storage sites in A. halleri.},
language = {en}
}
@article{JonesGonzalezFortesConnelletal.2015,
author = {Jones, Eppie R. and Gonz{\´a}lez-Fortes, Gloria M. and Connell, Sarah and Siska, Veronika and Eriksson, Anders and Martiniano, Rui and McLaughlin, Russell L. and Llorente, Marcos Gallego and Cassidy, Lara M. and Gamba, Cristina and Meshveliani, Tengiz and Bar-Yosef, Ofer and Mueller, Werner and Belfer-Cohen, Anna and Matskevich, Zinovi and Jakeli, Nino and Higham, Thomas F. G. and Currat, Mathias and Lordkipanidze, David and Hofreiter, Michael and Manica, Andrea and Pinhasi, Ron and Bradley, Daniel G.},
title = {Upper Palaeolithic genomes reveal deep roots of modern Eurasians},
series = {Nature Communications},
volume = {6},
journal = {Nature Communications},
publisher = {Nature Publishing Group},
address = {London},
issn = {2041-1723},
doi = {10.1038/ncomms9912},
pages = {8},
year = {2015},
abstract = {We extend the scope of European palaeogenomics by sequencing the genomes of Late Upper Palaeolithic (13,300 years old, 1.4-fold coverage) and Mesolithic (9,700 years old, 15.4-fold) males from western Georgia in the Caucasus and a Late Upper Palaeolithic (13,700 years old, 9.5-fold) male from Switzerland. While we detect Late Palaeolithic-Mesolithic genomic continuity in both regions, we find that Caucasus hunter-gatherers (CHG) belong to a distinct ancient clade that split from western hunter-gatherers similar to 45 kya, shortly after the expansion of anatomically modern humans into Europe and from the ancestors of Neolithic farmers similar to 25 kya, around the Last Glacial Maximum. CHG genomes significantly contributed to the Yamnaya steppe herders who migrated into Europe similar to 3,000 BC, supporting a formative Caucasus influence on this important Early Bronze age culture. CHG left their imprint on modern populations from the Caucasus and also central and south Asia possibly marking the arrival of Indo-Aryan languages.},
language = {en}
}
@article{KiemelGurkeParaskevopoulouetal.2022,
author = {Kiemel, Katrin and Gurke, Marie and Paraskevopoulou, Sofia and Havenstein, Katja and Weithoff, Guntram and Tiedemann, Ralph},
title = {Variation in heat shock protein 40 kDa relates to divergence in thermotolerance among cryptic rotifer species},
series = {Scientific Reports},
volume = {12},
journal = {Scientific Reports},
publisher = {Springer Nature},
address = {London},
issn = {2045-2322},
doi = {10.1038/s41598-022-27137-3},
pages = {14},
year = {2022},
abstract = {Genetic divergence and the frequency of hybridization are central for defining species delimitations, especially among cryptic species where morphological differences are merely absent. Rotifers are known for their high cryptic diversity and therefore are ideal model organisms to investigate such patterns. Here, we used the recently resolved Brachionus calyciflorus species complex to investigate whether previously observed between species differences in thermotolerance and gene expression are also reflected in their genomic footprint. We identified a Heat Shock Protein gene (HSP 40 kDa) which exhibits cross species pronounced sequence variation. This gene exhibits species-specific fixed sites, alleles, and sites putatively under positive selection. These sites are located in protein binding regions involved in chaperoning and may therefore reflect adaptive diversification. By comparing three genetic markers (ITS, COI, HSP 40 kDa), we revealed hybridization events between the cryptic species. The low frequency of introgressive haplotypes/alleles suggest a tight, but not fully impermeable boundary between the cryptic species.},
language = {en}
}
@article{KindermannDoblerNiedeggenetal.2022,
author = {Kindermann, Liana and Dobler, Magnus and Niedeggen, Daniela and Chimbioputo Fabiano, Ezequiel and Linst{\"a}dter, Anja},
title = {Dataset on woody aboveground biomass, disturbance losses, and wood density from an African savanna ecosystem},
series = {Data in Brief},
volume = {42},
journal = {Data in Brief},
publisher = {Elsevier},
address = {Amsterdam, Niederlande},
issn = {2352-3409},
doi = {10.1016/j.dib.2022.108155},
pages = {1 -- 16},
year = {2022},
abstract = {This dataset comprises tree inventories and damage assessments performed in Namibia's semi-arid Zambezi Region. Data were sampled in savannas and savanna woodlands along steep gradients of elephant population densities to capture the effects of those (and other) disturbances on individual-level and stand-level aboveground woody biomass (AGB). The dataset contains raw data on dendrometric measures and processed data on specific wood density (SWD), woody aboveground biomass, and biomass losses through disturbance impacts. Allometric proxies (height, canopy diameters, and in adult trees also stem circumferences) were recorded for n = 6,179 tree and shrub individuals. Wood samples were taken for each encountered species to measure specific wood density. These measurements have been used to estimate woody aboveground biomass via established allometric models, advanced through our improved methodologies and workflows that accounted for tree and shrub architecture shaped by disturbance impacts. To this end, we performed a detailed damage assessment on each woody individual in the field. In addition to estimations of standing biomass, our new method also delivered data on biomass losses to different disturbance agents (elephants, fire, and others) on the level of plant individuals and stands. The data presented here have been used within a study published with Ecological Indicators (Kindermann et al., 2022) to evaluate the benefits of our improved methodology in comparison to a standard reference method of aboveground biomass estimations. Additionally, it has been employed in a study on carbon storage and sequestration in vegetation and soils (Sandhage-Hofmann et al., 2021). The raw data of dendrometric measurements can be subjected to other available allometric models for biomass estimation. The processed data can be used to analyze disturbance impacts on woody aboveground biomass, or for regional carbon storage estimates. The data on species-specific wood density can be used for application to other dendrometric datasets to (re-) estimate biomass through allometric models requiring wood density. It can further be used for plant functional trait analyses.},
language = {en}
}
@phdthesis{Kluth2012,
author = {Kluth, Oliver},
title = {Einfluss von Glucolipotoxizit{\"a}t auf die Funktion der β-Zellen diabetessuszeptibler und -resistenter Mausst{\"a}mme},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-61961},
school = {Universit{\"a}t Potsdam},
year = {2012},
abstract = {Ziel der vorliegenden Arbeit war es, die Auswirkungen von Glucose- und Lipidtoxizit{\"a}t auf die Funktion der β-Zellen von Langerhans-Inseln in einem diabetesresistenten (B6.V-Lepob/ob, ob/ob) sowie diabetessuszeptiblen (New Zealand Obese, NZO) Mausmodell zu untersuchen. Es sollten molekulare Mechanismen identifiziert werden, die zum Untergang der β-Zellen in der NZO-Maus f{\"u}hren bzw. zum Schutz der β-Zellen der ob/ob-Maus beitragen. Zun{\"a}chst wurde durch ein geeignetes di{\"a}tetisches Regime in beiden Modellen durch kohlenhydratrestriktive Ern{\"a}hrung eine Adipositas(Lipidtoxizit{\"a}t) induziert und anschließend durch F{\"u}tterung einer kohlenhydrathaltigen Di{\"a}t ein Zustand von Glucolipotoxizit{\"a}t erzeugt. Dieses Vorgehen erlaubte es, in der NZO-Maus in einem kurzen Zeitfenster eine Hyperglyk{\"a}mie sowie einen β-Zelluntergang durch Apoptose auszul{\"o}sen. Im Vergleich dazu blieben ob/ob-M{\"a}use l{\"a}ngerfristig normoglyk{\"a}misch und wiesen keinen β-Zelluntergang auf. Die Ursache f{\"u}r den β-Zellverlust war die Inaktivierung des Insulin/IGF-1-Rezeptor-Signalwegs, wie durch Abnahme von phospho-AKT, phospho-FoxO1 sowie des β-zellspezifischen Transkriptionsfaktors PDX1 gezeigt wurde. Mit Ausnahme des Effekts einer Dephosphorylierung von FoxO1, konnten ob/ob-M{\"a}use diesen Signalweg aufrechterhalten und dadurch einen Verlust von β-Zellen abwenden. Die glucolipotoxischen Effekte wurden in vitro an isolierten Inseln beider St{\"a}mme und der β-Zelllinie MIN6 best{\"a}tigt und zeigten, dass ausschließlich die Kombination hoher Glucose und Palmitatkonzentrationen (Glucolipotoxizit{\"a}t) negative Auswirkungen auf die NZO-Inseln und MIN6-Zellen hatte, w{\"a}hrend ob/ob-Inseln davor gesch{\"u}tzt blieben. Die Untersuchung isolierter Inseln ergab, dass beide St{\"a}mme unter glucolipotoxischen Bedingungen keine Steigerung der Insulinexpression aufweisen und sich bez{\"u}glich ihrer Glucose-stimulierten Insulinsekretion nicht unterscheiden. Mit Hilfe von Microarray- sowie immunhistologischen Untersuchungen wurde gezeigt, dass ausschließlich ob/ob-M{\"a}use nach Kohlenhydratf{\"u}tterung eine kompensatorische transiente Induktion der β-Zellproliferation aufwiesen, die in einer nahezu Verdreifachung der Inselmasse nach 32 Tagen m{\"u}ndete. Die hier erzielten Ergebnisse lassen die Schlussfolgerung zu, dass der β-Zelluntergang der NZO-Maus auf eine Beeintr{\"a}chtigung des Insulin/IGF-1-Rezeptor-Signalwegs sowie auf die Unf{\"a}higkeit zur β- Zellproliferation zur{\"u}ckgef{\"u}hrt werden kann. Umgekehrt erm{\"o}glichen der Erhalt des Insulin/IGF-1-Rezeptor-Signalwegs und die Induktion der β-Zellproliferation in der ob/ob-Maus den Schutz vor einer Hyperglyk{\"a}mie und einem Diabetes.},
language = {de}
}
@article{KruegerFoersterTrauthetal.2021,
author = {Kr{\"u}ger, Johanna and Foerster, Verena Elisabeth and Trauth, Martin H. and Hofreiter, Michael and Tiedemann, Ralph},
title = {Exploring the Past Biosphere of Chew Bahir/Southern Ethiopia: Cross-Species Hybridization Capture of Ancient Sedimentary DNA from a Deep Drill Core},
series = {Frontiers in Earth Science},
journal = {Frontiers in Earth Science},
publisher = {Frontiers in Earth Science},
address = {Lausanne, Schweiz},
issn = {2296-6463},
doi = {10.3389/feart.2021.683010},
pages = {1 -- 20},
year = {2021},
abstract = {Eastern Africa has been a prime target for scientific drilling because it is rich in key paleoanthropological sites as well as in paleolakes, containing valuable paleoclimatic information on evolutionary time scales. The Hominin Sites and Paleolakes Drilling Project (HSPDP) explores these paleolakes with the aim of reconstructing environmental conditions around critical episodes of hominin evolution. Identification of biological taxa based on their sedimentary ancient DNA (sedaDNA) traces can contribute to understand past ecological and climatological conditions of the living environment of our ancestors. However, sedaDNA recovery from tropical environments is challenging because high temperatures, UV irradiation, and desiccation result in highly degraded DNA. Consequently, most of the DNA fragments in tropical sediments are too short for PCR amplification. We analyzed sedaDNA in the upper 70 m of the composite sediment core of the HSPDP drill site at Chew Bahir for eukaryotic remnants. We first tested shotgun high throughput sequencing which leads to metagenomes dominated by bacterial DNA of the deep biosphere, while only a small fraction was derived from eukaryotic, and thus probably ancient, DNA. Subsequently, we performed cross-species hybridization capture of sedaDNA to enrich ancient DNA (aDNA) from eukaryotic remnants for paleoenvironmental analysis, using established barcoding genes (cox1 and rbcL for animals and plants, respectively) from 199 species that may have had relatives in the past biosphere at Chew Bahir. Metagenomes yielded after hybridization capture are richer in reads with similarity to cox1 and rbcL in comparison to metagenomes without prior hybridization capture. Taxonomic assignments of the reads from these hybridization capture metagenomes also yielded larger fractions of the eukaryotic domain. For reads assigned to cox1, inferred wet periods were associated with high inferred relative abundances of putative limnic organisms (gastropods, green algae), while inferred dry periods showed increased relative abundances for insects. These findings indicate that cross-species hybridization capture can be an effective approach to enhance the information content of sedaDNA in order to explore biosphere changes associated with past environmental conditions, enabling such analyses even under tropical conditions.},
language = {en}
}
@misc{Koechert2007,
type = {Master Thesis},
author = {K{\"o}chert, Karl},
title = {Development of a method to assess EAAT1 transcription levels in Alzheimer's disease},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15965},
school = {Universit{\"a}t Potsdam},
year = {2007},
abstract = {Zur Zeit leiden ca. 24 Millionen Menschen auf der ganzen Welt unter Demenz, Alzheimer macht dabei 50-60\% aller Demenzf{\"a}lle aus. Da der Anteil der Bev{\"o}lkerung, der an Demenz leidet, proportional zum Alter zunimmt und der Anteil {\"a}lterer Menschen in der Gesellschaft von Jahr zu Jahr steigt, wird Alzheimer immer mehr zu einem ernstzunehmenden, gesellschaftlichen Problem. Zum Stand der heutigen Forschung ist es etabliert, dass die Aminos{\"a}ure Glutamat - quantitativ einer der wichtigsten Neurotransmitter im Zentralen Nervensystem (ZNS) - toxische Konzentrationen erreichen kann wenn sie - im Zuge der {\"U}bertragung von Aktionspotentialen - nach ihrer Freisetzung nicht aus dem Synaptischen Spalt entfernt wird. Viele Studien haben gezeigt, dass in der Alzheimerschen Krankheit die Glutamataufnahme beeintr{\"a}chtigt ist, was zu toxischen Konzentrationen von Glutamat und dem daraus folgenden Absterben von Neuronen f{\"u}hrt. Der exitatorische Aminos{\"a}uretransporter 1 (EAAT1) geh{\"o}rt zu der Familie der Na+-abh{\"a}ngigen Glutamattransporter und stellt nach EAAT2 den quantitativ wichtigsten Glutamattransporter im ZNS dar. In diesem Projekt wurde eine bis dahin f{\"u}r den Menschen nicht bekannte EAAT1 Spleißvariante, in der Exon 3 ausgeschnitten wird, nachgewiesen. Diese Variante wurde EAAT1Δ3 genannt und stellt damit mit EAAT1Δ9 die zweite f{\"u}r EAAT1 nachgewiesene Spleißvariante dar. Eine auf real-time RT-PCR basierende Methode wurde entwickelt, um die Transkripte von EAAT1 wildtyp (EAAT1 wt), EAAT1Δ3 und EAAT1Δ9 zu quantifizieren. Proben aus verschiedenen Hirnarealen wurden aus einem Set von Kontrollen und Alzheimerf{\"a}llen bei der Quantifizierung verwendet. Die gew{\"a}hlten Areale sind von der Alzheimerschen Krankheit unterschiedlich stark betroffen. Dies diente als interne Kontrolle f{\"u}r die durchgef{\"u}hrten Experimente und erm{\"o}glichte so die Differenzierung zwischen beobachteten Effekten: Nur Effekte die alleinig in von Alzheimer betroffenen Gehirnarealen auftreten, k{\"o}nnen als spezifisch f{\"u}r die Krankheit angesehen werden. Die Resultate diese Projektes zeigen, dass EAAT1Δ3 in sehr geringer Anzahl transkribiert wird, die nur 0.15\% der EAAT1 wt Transkription entspricht. Dahingegen entspricht das EAAT1 Δ9 Transkript im Durchschnitt 26.6\% des EAAT1 wt Transkripts. Es wurde nachgewiesen, dass die Transkriptionsrate aller EAAT1 Varianten in Alzheimerf{\"a}llen signifikant reduziert ist (P<0.0001). Dies unterst{\"u}tzt die Theorie, dass bei Alzheimerf{\"a}llen die EAAT1 Proteinexpression stark reduziert und der Glutamattransport, der normalerweise durch diesen Transporter gew{\"a}hrleistet wird, stark eingeschr{\"a}nkt ist. Dies wiederum resultiert in toxisch hohen Glutamatkonzentrationen und damit dem Absterben von Neuronen. Die gefundene Reduktion der EAAT1Transkription ist nicht spezifisch f{\"u}r Gehirnareale die von Alzheimer betroffen sind, sondern tritt in selbem Maße in nicht von Alzheimer betroffenen Gehirnarealen auf. Daraus l{\"a}sst sich schließen, dass die Reduktion der EAAT1 Transkription eher ein Resultat eines in der Alzheimerschen Krankheit pr{\"a}senten, grundlegenden Krankheitsmechanismus ist als deren Ursache.},
language = {en}
}
@misc{KoechyBrakenhielm2008,
author = {K{\"o}chy, Martin and Br{\aa}kenhielm, Sven},
title = {Separation of effects of moderate N deposition from natural change in ground vegetation of forests and bogs},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16621},
year = {2008},
abstract = {The effect of moderate rates of nitrogen deposition on ground floor vegetation is poorly predicted by uncontrolled surveys or fertilization experiments using high rates of nitrogen (N) addition. We compared the temporal trends of ground floor vegetation in permanent plots with moderate (7-13 kg ha-1 year-1) and lower bulk N deposition (4-6 kg ha-1 year-1) in southern Sweden during 1982-1998. We examined whether trends differed between growth forms (vascular plants and bryophytes) and vegetation types (three types of coniferous forest, deciduous forest, and bog). Trends of site-standardized cover and richness varied among growth forms, vegetation types, and deposition regions. Cover in spruce forests decreased at the same rate with both moderate and low deposition. In pine forests cover decreased faster with moderate deposition and in bogs cover decreased faster with low deposition. Cover of bryophytes in spruce forests increased at the same rate with both moderate and low deposition. In pine forests cover decreased faster with moderate deposition and in bogs and deciduous forests there was a strong non-linear increase with moderate deposition. The trend of number of vascular plants was constant with moderate and decreased with low deposition. We found no trend in the number of bryophyte species. We propose that the decrease of cover and number with low deposition was related to normal ecosystem development (increased shading), suggesting that N deposition maintained or increased the competitiveness of some species in the moderate-deposition region. Deposition had no consistent negative effect on vegetation suggesting that it is less important than normal successional processes.},
language = {en}
}
@misc{KoechyMathajJeltschetal.2008,
author = {K{\"o}chy, Martin and Mathaj, Martin and Jeltsch, Florian and Malkinson, Dan},
title = {Resilience of stocking capacity to changing climate in arid to Mediterranean landscapes},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18720},
year = {2008},
abstract = {Small livestock is an important resource for rural human populations in dry climates. How strongly will climate change affect the capacity of the rangeland? We used hierarchical modelling to scale quantitatively the growth of shrubs and annual plants, the main food of sheep and goats, to the landscape extent in the eastern Mediterranean region. Without grazing, productivity increased in a sigmoid way with mean annual precipitation. Grazing reduced productivity more strongly the drier the landscape. At a point just under the stocking capacity of the vegetation, productivity declined precipitously with more intense grazing due to a lack of seed production of annuals. We repeated simulations with precipitation patterns projected by two contrasting IPCC scenarios. Compared to results based on historic patterns, productivity and stocking capacity did not differ in most cases. Thus, grazing intensity remains the stronger impact on landscape productivity in this dry region even in the future.},
language = {en}
}
@inproceedings{KuehlingMaerkerZehe2006,
author = {K{\"u}hling, Matthias and M{\"a}rker, Michael and Zehe, Erwin},
title = {Musterdynamik und Fernerkundung in der D{\"o}beritzer Heide : [Poster]},
editor = {Gzik, Axel and Hochschild, Volker and Schneider, Ingo and Schr{\"o}der, Boris},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7277},
year = {2006},
abstract = {Mit der politischen Wende in den Staaten des ehemaligen Ostblockes wurde f{\"u}r viele milit{\"a}risch genutzte Fl{\"a}chen ein tiefgreifender Nutzungswandel eingeleitet. Truppen{\"u}bungspl{\"a}tze als stark gest{\"o}rte Bestandteile unserer Kulturlandschaft weisen auf großen Fl{\"a}chen naturschutzfachlich wertvolle Habitatmosaike mit speziellen Lebensgemeinschaften auf. Der Nutzungswandel ist mit einer Ver{\"a}nderung der Vegetationsstrukturen (Sukzession) und weiteren landschafts{\"o}kologischen Prozessen verbunden. Der ehemalige Truppen{\"u}bungsplatz D{\"o}beritz im Norden der Landeshauptstadt Potsdam kann auf eine lange milit{\"a}rische Nutzungsgeschichte verweisen (erste Man{\"o}ver des Soldatenk{\"o}nigs im Jahr 1713). Nach 1992 wurden das NSG D{\"o}beritzer Heide (3.415 ha) und das NSG Ferbitzer Bruch (1.155 ha) ausgewiesen. Als Schutzgebiete nach der Vogelschutzrichtlinie sind sie Bestandteile des koh{\"a}renten Schutzgebietssystems Natura 2000 der europ{\"a}ischen Gemeinschaft. Trotz des Schutzstatus und der milit{\"a}rischen Altlasten unterliegt das Gebiet als gr{\"o}ßte zusammenh{\"a}ngende Naturfl{\"a}che im engeren Verflechtungsraum des Landes Brandenburg einem hohen Nutzungsdruck.
Interdisziplin{\"a}res Zentrum f{\"u}r Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006},
language = {de}
}
@article{LiuZhouFettke2021,
author = {Liu, Qingting and Zhou, Yuan and Fettke, J{\"o}rg},
title = {Starch granule size and morphology of Arabidopsis thaliana starch-related mutants analyzed during diurnal rhythm and development},
series = {Molecules : a journal of synthetic chemistry and natural product chemistry / Molecular Diversity Preservation International},
volume = {26},
journal = {Molecules : a journal of synthetic chemistry and natural product chemistry / Molecular Diversity Preservation International},
edition = {19},
publisher = {MDPI},
address = {Basel, Schweiz},
issn = {1420-3049},
doi = {10.3390/molecules26195859},
pages = {1 -- 9},
year = {2021},
abstract = {Transitory starch plays a central role in the life cycle of plants. Many aspects of this important metabolism remain unknown; however, starch granules provide insight into this persistent metabolic process. Therefore, monitoring alterations in starch granules with high temporal resolution provides one significant avenue to improve understanding. Here, a previously established method that combines LCSM and safranin-O staining for in vivo imaging of transitory starch granules in leaves of Arabidopsis thaliana was employed to demonstrate, for the first time, the alterations in starch granule size and morphology that occur both throughout the day and during leaf aging. Several starch-related mutants were included, which revealed differences among the generated granules. In ptst2 and sex1-8, the starch granules in old leaves were much larger than those in young leaves; however, the typical flattened discoid morphology was maintained. In ss4 and dpe2/phs1/ss4, the morphology of starch granules in young leaves was altered, with a more rounded shape observed. With leaf development, the starch granules became spherical exclusively in dpe2/phs1/ss4. Thus, the presented data provide new insights to contribute to the understanding of starch granule morphogenesis.},
language = {en}
}
@article{MarggrafLindeckeVoigtetal.2023,
author = {Marggraf, Lara Christin and Lindecke, Oliver and Voigt, Christian C. and Pētersons, Gunārs and Voigt-Heucke, Silke Luise},
title = {Nathusius' bats, Pipistrellus nathusii, bypass mating opportunities of their own species, but respond to foraging heterospecifics on migratory transit flights},
series = {Frontiers in Ecology and Evolution},
journal = {Frontiers in Ecology and Evolution},
publisher = {Frontiers},
address = {Lausanne, Schweiz},
issn = {2296-701X},
doi = {10.3389/fevo.2022.908560},
pages = {1 -- 10},
year = {2023},
abstract = {In late summer, migratory bats of the temperate zone face the challenge of accomplishing two energy-demanding tasks almost at the same time: migration and mating. Both require information and involve search efforts, such as localizing prey or finding potential mates. In non-migrating bat species, playback studies showed that listening to vocalizations of other bats, both con-and heterospecifics, may help a recipient bat to find foraging patches and mating sites. However, we are still unaware of the degree to which migrating bats depend on con-or heterospecific vocalizations for identifying potential feeding or mating opportunities during nightly transit flights. Here, we investigated the vocal responses of Nathusius' pipistrelle bats, Pipistrellus nathusii, to simulated feeding and courtship aggregations at a coastal migration corridor. We presented migrating bats either feeding buzzes or courtship calls of their own or a heterospecific migratory species, the common noctule, Nyctalus noctula. We expected that during migratory transit flights, simulated feeding opportunities would be particularly attractive to bats, as well as simulated mating opportunities which may indicate suitable roosts for a stopover. However, we found that when compared to the natural silence of both pre-and post-playback phases, bats called indifferently during the playback of conspecific feeding sounds, whereas P. nathusii echolocation call activity increased during simulated feeding of N. noctula. In contrast, the call activity of P. nathusii decreased during the playback of conspecific courtship calls, while no response could be detected when heterospecific call types were broadcasted. Our results suggest that while on migratory transits, P. nathusii circumnavigate conspecific mating aggregations, possibly to save time or to reduce the risks associated with social interactions where aggression due to territoriality might be expected. This avoidance behavior could be a result of optimization strategies by P. nathusii when performing long-distance migratory flights, and it could also explain the lack of a response to simulated conspecific feeding. However, the observed increase of activity in response to simulated feeding of N. noctula, suggests that P. nathusii individuals may be eavesdropping on other aerial hawking insectivorous species during migration, especially if these occupy a slightly different foraging niche.},
language = {en}
}
@phdthesis{Martin2013,
author = {Martin, Benjamin},
title = {Linking individual-based models and dynamic energy budget theory : lessons for ecology and ecotoxicology},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-67001},
school = {Universit{\"a}t Potsdam},
year = {2013},
abstract = {In the context of ecological risk assessment of chemicals, individual-based population models hold great potential to increase the ecological realism of current regulatory risk assessment procedures. However, developing and parameterizing such models is time-consuming and often ad hoc. Using standardized, tested submodels of individual organisms would make individual-based modelling more efficient and coherent. In this thesis, I explored whether Dynamic Energy Budget (DEB) theory is suitable for being used as a standard submodel in individual-based models, both for ecological risk assessment and theoretical population ecology. First, I developed a generic implementation of DEB theory in an individual-based modeling (IBM) context: DEB-IBM. Using the DEB-IBM framework I tested the ability of the DEB theory to predict population-level dynamics from the properties of individuals. We used Daphnia magna as a model species, where data at the individual level was available to parameterize the model, and population-level predictions were compared against independent data from controlled population experiments. We found that DEB theory successfully predicted population growth rates and peak densities of experimental Daphnia populations in multiple experimental settings, but failed to capture the decline phase, when the available food per Daphnia was low. Further assumptions on food-dependent mortality of juveniles were needed to capture the population dynamics after the initial population peak. The resulting model then predicted, without further calibration, characteristic switches between small- and large-amplitude cycles, which have been observed for Daphnia. We conclude that cross-level tests help detecting gaps in current individual-level theories and ultimately will lead to theory development and the establishment of a generic basis for individual-based models and ecology. In addition to theoretical explorations, we tested the potential of DEB theory combined with IBMs to extrapolate effects of chemical stress from the individual to population level. For this we used information at the individual level on the effect of 3,4-dichloroanailine on Daphnia. The individual data suggested direct effects on reproduction but no significant effects on growth. Assuming such direct effects on reproduction, the model was able to accurately predict the population response to increasing concentrations of 3,4-dichloroaniline. We conclude that DEB theory combined with IBMs holds great potential for standardized ecological risk assessment based on ecological models.},
language = {en}
}
@phdthesis{Mubeen2018,
author = {Mubeen, Umarah},
title = {Regulation of central carbon and nitrogen metabolism by Target of Rapamycin (TOR) kinase in Chlamydomonas reinhardtii},
school = {Universit{\"a}t Potsdam},
pages = {vii, 153},
year = {2018},
abstract = {The highly conserved protein complex containing the Target of Rapamycin (TOR) kinase is known to integrate intra- and extra-cellular stimuli controlling nutrient allocation and cellular growth. This thesis describes three studies aimed to understand how TOR signaling pathway influences carbon and nitrogen metabolism in Chlamydomonas reinhardtii. The first study presents a time-resolved analysis of the molecular and physiological features across the diurnal cycle. The inhibition of TOR leads to 50\% reduction in growth followed by nonlinear delays in the cell cycle progression. The metabolomics analysis showed that the growth repression is mainly driven by differential carbon partitioning between anabolic and catabolic processes. Furthermore, the high accumulation of nitrogen-containing compounds indicated that TOR kinase controls the carbon to nitrogen balance of the cell, which is responsible for biomass accumulation, growth and cell cycle progression. In the second study the cause of the high accumulation of amino acids is explained. For this purpose, the effect of TOR inhibition on Chlamydomonas was examined under different growth regimes using stable 13C- and 15N-isotope labeling. The data clearly showed that an increased nitrogen uptake is induced within minutes after the inhibition of TOR. Interestingly, this increased N-influx is accompanied by increased activities of nitrogen assimilating enzymes. Accordingly, it was concluded that TOR inhibition induces de-novo amino acid synthesis in Chlamydomonas. The recognition of this novel process opened an array of questions regarding potential links between central metabolism and TOR signaling. Therefore a detailed phosphoproteomics study was conducted to identify the potential substrates of TOR pathway regulating central metabolism. Interestingly, some of the key enzymes involved in carbon metabolism as well as amino acid synthesis exhibited significant changes in the phosphosite intensities immediately after TOR inhibition. Altogether, these studies provide a) detailed insights to metabolic response of Chlamydomonas to TOR inhibition, b) identification of a novel process causing rapid upshifts in amino acid levels upon TOR inhibition and c) finally highlight potential targets of TOR signaling regulating changes in central metabolism. Further biochemical and molecular investigations could confirm these observations and advance the understanding of growth signaling in microalgae.},
language = {en}
}
@article{MummHermanussen2022,
author = {Mumm, Rebekka and Hermanussen, Michael},
title = {The dilemma of misclassifying weight in short and in historic population},
series = {Human biology and public health},
volume = {2021},
journal = {Human biology and public health},
number = {3, Summer School Supplement},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph2021.3.28},
pages = {7},
year = {2022},
abstract = {Background: Clinicians often refer anthropometric measures of a child to so-called "growth standards" and "growth references. Over 140 countries have meanwhile adopted WHO growth standards. Objectives: The present study was conducted to thoroughly examine the idea of growth standards as a common yardstick for all populations. Weight depends on height. We became interested in whether also weight-for-height depends on height. First, we studied the age-group effect on weight-for-height. Thereafter, we tested the applicability of weight-for-height references in short and in historic populations. Sample and Methods: We analyzed body height and body weight and weight-for-height of 3795 healthy boys and 3726 healthy girls aged 2 to 5 years measured in East-Germany between 1986 and 1990. We chose contemporary height and weight charts from Germany, the UK, and the WHO growth chart and compared these with three geographically commensurable growth charts from the end of the 19th century. Results: We analyzed body height and body weight and weight-for-height of 3795 healthy boys and 3726 healthy girls aged 2 to 5 years measured in East-Germany between 1986 and 1990. We chose contemporary height and weight charts from Germany, the UK, and the WHO growth chart and compared these with three geographically commensurable growth charts of the end of the 19th century. Conclusion: Weight-for-height depends on age and sex and apart from the nutritional state, reflects body proportion and body built particularly during infancy and early childhood. Populations with a relatively short average height are prone to high values of weight-for-height for arithmetic reasons independent of the nutritional state.},
language = {en}
}
@article{MummSchefflerHermanussen2022,
author = {Mumm, Rebekka and Scheffler, Christiane and Hermanussen, Michael},
title = {Locally structured correlation (LSC) plots describe inhomogeneity in normally distributed correlated bivariate variables},
series = {Archives of Public Health},
volume = {80},
journal = {Archives of Public Health},
publisher = {Springer Nature BMC},
address = {Bruxelles},
issn = {0778-7367},
doi = {10.1186/s13690-021-00748-4},
pages = {6},
year = {2022},
abstract = {Background The association between bivariate variables may not necessarily be homogeneous throughout the whole range of the variables. We present a new technique to describe inhomogeneity in the association of bivariate variables. Methods We consider the correlation of two normally distributed random variables. The 45° diagonal through the origin of coordinates represents the line on which all points would lie if the two variables completely agreed. If the two variables do not completely agree, the points will scatter on both sides of the diagonal and form a cloud. In case of a high association between the variables, the band width of this cloud will be narrow, in case of a low association, the band width will be wide. The band width directly relates to the magnitude of the correlation coefficient. We then determine the Euclidean distances between the diagonal and each point of the bivariate correlation, and rotate the coordinate system clockwise by 45°. The standard deviation of all Euclidean distances, named "global standard deviation", reflects the band width of all points along the former diagonal. Calculating moving averages of the standard deviation along the former diagonal results in "locally structured standard deviations" and reflect patterns of "locally structured correlations (LSC)". LSC highlight inhomogeneity of bivariate correlations. We exemplify this technique by analyzing the association between body mass index (BMI) and hip circumference (HC) in 6313 healthy East German adults aged 18 to 70 years. Results The correlation between BMI and HC in healthy adults is not homogeneous. LSC is able to identify regions where the predictive power of the bivariate correlation between BMI and HC increases or decreases, and highlights in our example that slim people have a higher association between BMI and HC than obese people. Conclusion Locally structured correlations (LSC) identify regions of higher or lower than average correlation between two normally distributed variables.},
language = {en}
}
@article{NovineMattssonGroth2022,
author = {Novine, Masiar and Mattsson, Cecilie Cordua and Groth, Detlef},
title = {Network reconstruction based on synthetic data generated by a Monte Carlo approach},
series = {Human biology and public health},
volume = {2021},
journal = {Human biology and public health},
number = {3, Summer School Supplement},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph2021.3.26},
pages = {23},
year = {2022},
abstract = {Background: Network models are useful tools for researchers to simplify and understand investigated systems. Yet, the assessment of methods for network construction is often uncertain. Random resampling simulations can aid to assess methods, provided synthetic data exists for reliable network construction. Objectives: We implemented a new Monte Carlo algorithm to create simulated data for network reconstruction, tested the influence of adjusted parameters and used simulations to select a method for network model estimation based on real-world data. We hypothesized, that reconstructs based on Monte Carlo data are scored at least as good compared to a benchmark. Methods: Simulated data was generated in R using the Monte Carlo algorithm of the mcgraph package. Benchmark data was created by the huge package. Networks were reconstructed using six estimator functions and scored by four classification metrics. For compatibility tests of mean score differences, Welch's t-test was used. Network model estimation based on real-world data was done by stepwise selection. Samples: Simulated data was generated based on 640 input graphs of various types and sizes. The real-world dataset consisted of 67 medieval skeletons of females and males from the region of Refshale (Lolland) and Nordby (Jutland) in Denmark. Results: Results after t-tests and determining confidence intervals (CI95\%) show, that evaluation scores for network reconstructs based on the mcgraph package were at least as good compared to the benchmark huge. The results even indicate slightly better scores on average for the mcgraph package. Conclusion: The results confirmed our objective and suggested that Monte Carlo data can keep up with the benchmark in the applied test framework. The algorithm offers the feature to use (weighted) un- and directed graphs and might be useful for assessing methods for network construction.},
language = {en}
}
@phdthesis{Oey2008,
author = {Oey, Melanie},
title = {Chloroplasts as bioreactors : high-yield production of active bacteriolytic protein antibiotics},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-28950},
school = {Universit{\"a}t Potsdam},
year = {2008},
abstract = {Plants, more precisely their chloroplasts with their bacterial-like expression machinery inherited from their cyanobacterial ancestors, can potentially offer a cheap expression system for proteinaceous pharmaceuticals. This system would be easily scalable and provides appropriate safety due to chloroplasts maternal inheritance. In this work, it was shown that three phage lytic enzymes (Pal, Cpl-1 and PlyGBS) could be successfully expressed at very high levels and with high stability in tobacco chloroplasts. PlyGBS expression reached an amount of foreign protein accumulation (> 70\% TSP) that has never been obtained before. Although the high expression levels of PlyGBS caused a pale green phenotype with retarded growth, presumably due to exhaustion of plastid protein synthesis capacity, development and seed production were not impaired under greenhouse conditions. Since Pal and Cpl-1 showed toxic effects when expressed in E. coli, a special plastid transformation vector (pTox) was constructed to allow DNA amplification in bacteria. The construction of the pTox transformation vector allowing a recombinase-mediated deletion of an E. coli transcription block in the chloroplast, leading to an increase of foreign protein accumulation to up to 40\% of TSP for Pal and 20\% of TSP for Cpl-1. High dose-dependent bactericidal efficiency was shown for all three plant-derived lytic enzymes using their pathogenic target bacteria S. pyogenes and S. pneumoniae. Confirmation of specificity was obtained for the endotoxic proteins Pal and Cpl-1 by application to E. coli cultures. These results establish tobacco chloroplasts as a new cost-efficient and convenient production platform for phage lytic enzymes and address the greatest obstacle for clinical application. The present study is the first report of lysin production in a non-bacterial system. The properties of chloroplast-produced lysins described in this work, their stability, high accumulation rate and biological activity make them highly attractive candidates for future antibiotics.},
language = {en}
}
@article{OgunkolaGuiraudieCaprazFeronetal.2023,
author = {Ogunkola, Moses Olalekan and Guiraudie-Capraz, Gaelle and F{\´e}ron, Fran{\c{c}}ois and Leimk{\"u}hler, Silke},
title = {The Human Mercaptopyruvate Sulfurtransferase TUM1 Is Involved in Moco Biosynthesis, Cytosolic tRNA Thiolation and Cellular Bioenergetics in Human Embryonic Kidney Cells},
series = {Biomolecules},
volume = {13},
journal = {Biomolecules},
edition = {1},
publisher = {MDPI},
address = {Basel, Schweiz},
issn = {2218-273X},
doi = {10.3390/biom13010144},
pages = {1 -- 23},
year = {2023},
abstract = {Sulfur is an important element that is incorporated into many biomolecules in humans. The incorporation and transfer of sulfur into biomolecules is, however, facilitated by a series of different sulfurtransferases. Among these sulfurtransferases is the human mercaptopyruvate sulfurtransferase (MPST) also designated as tRNA thiouridine modification protein (TUM1). The role of the human TUM1 protein has been suggested in a wide range of physiological processes in the cell among which are but not limited to involvement in Molybdenum cofactor (Moco) biosynthesis, cytosolic tRNA thiolation and generation of H2S as signaling molecule both in mitochondria and the cytosol. Previous interaction studies showed that TUM1 interacts with the L-cysteine desulfurase NFS1 and the Molybdenum cofactor biosynthesis protein 3 (MOCS3). Here, we show the roles of TUM1 in human cells using CRISPR/Cas9 genetically modified Human Embryonic Kidney cells. Here, we show that TUM1 is involved in the sulfur transfer for Molybdenum cofactor synthesis and tRNA thiomodification by spectrophotometric measurement of the activity of sulfite oxidase and liquid chromatography quantification of the level of sulfur-modified tRNA. Further, we show that TUM1 has a role in hydrogen sulfide production and cellular bioenergetics.},
language = {en}
}
@article{PawlakNoetzelDragoetal.2022,
author = {Pawlak, Julia and Noetzel, Dominique Christian and Drago, Claudia and Weithoff, Guntram},
title = {Assessing the toxicity of polystyrene beads and silica particles on the microconsumer Brachionus calyciflorus at different timescales},
series = {Frontiers in Environmental Science},
journal = {Frontiers in Environmental Science},
publisher = {Frontiers},
address = {Lausanne, Schweiz},
issn = {2296-665X},
doi = {10.3389/fenvs.2022.955425},
pages = {1 -- 11},
year = {2022},
abstract = {Environmental pollution by microplastics has become a severe problem in terrestrial and aquatic ecosystems and, according to actual prognoses, problems will further increase in the future. Therefore, assessing and quantifying the risk for the biota is crucial. Standardized short-term toxicological procedures as well as methods quantifying potential toxic effects over the whole life span of an animal are required. We studied the effect of the microplastic polystyrene on the survival and reproduction of a common freshwater invertebrate, the rotifer Brachionus calyciflorus, at different timescales. We used pristine polystyrene spheres of 1, 3, and 6 µm diameter and fed them to the animals together with food algae in different ratios ranging from 0 to 50\% nonfood particles. As a particle control, we used silica to distinguish between a pure particle effect and a plastic effect. After 24 h, no toxic effect was found, neither with polystyrene nor with silica. After 96 h, a toxic effect was detectable for both particle types. The size of the particles played a negligible role. Studying the long-term effect by using life table experiments, we found a reduced reproduction when the animals were fed with 3 µm spheres together with similar-sized food algae. We conclude that the fitness reduction is mainly driven by the dilution of food by the nonfood particles rather than by a direct toxic effect.},
language = {en}
}
@phdthesis{Pellegrino2022,
author = {Pellegrino, Antonio},
title = {miRNA profiling for diagnosis of chronic pain in polyneuropathy},
doi = {10.25932/publishup-58385},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-583858},
school = {Universit{\"a}t Potsdam},
pages = {viii, 97, xi},
year = {2022},
abstract = {This dissertation aimed to determine differential expressed miRNAs in the context of chronic pain in polyneuropathy. For this purpose, patients with chronic painful polyneuropathy were compared with age matched healthy patients. Taken together, all miRNA pre library preparation quality controls were successful and none of the samples was identified as an outlier or excluded for library preparation. Pre sequencing quality control showed that library preparation worked for all samples as well as that all samples were free of adapter dimers after BluePippin size selection and reached the minimum molarity for further processing. Thus, all samples were subjected to sequencing. The sequencing control parameters were in their optimal range and resulted in valid sequencing results with strong sample to sample correlation for all samples. The resulting FASTQ file of each miRNA library was analyzed and used to perform a differential expression analysis. The differentially expressed and filtered miRNAs were subjected to miRDB to perform a target prediction. Three of those four miRNAs were downregulated: hsa-miR-3135b, hsa-miR-584-5p and hsa-miR-12136, while one was upregulated: hsa-miR-550a-3p. miRNA target prediction showed that chronic pain in polyneuropathy might be the result of a combination of miRNA mediated high blood flow/pressure and neural activity dysregulations/disbalances. Thus, leading to the promising conclusion that these four miRNAs could serve as potential biomarkers for the diagnosis of chronic pain in polyneuropathy. Since TRPV1 seems to be one of the major contributors of nociception and is associated with neuropathic pain, the influence of PKA phosphorylated ARMS on the sensitivity of TRPV1 as well as the part of AKAP79 during PKA phosphorylation of ARMS was characterized. Therefore, possible PKA-sites in the sequence of ARMS were identified. This revealed five canonical PKA-sites: S882, T903, S1251/52, S1439/40 and S1526/27. The single PKA-site mutants of ARMS revealed that PKA-mediated ARMS phosphorylation seems not to influence the interaction rate of TRPV1/ARMS. While phosphorylation of ARMST903 does not increase the interaction rate with TRPV1, ARMSS1526/27 is probably not phosphorylated and leads to an increased interaction rate. The calcium flux measurements indicated that the higher the interaction rate of TRPV1/ARMS, the lower the EC50 for capsaicin of TRPV1, independent of the PKA phosphorylation status of ARMS. In addition, the western blot analysis confirmed the previously observed TRPV1/ARMS interaction. More importantly, AKAP79 seems to be involved in the TRPV1/ARMS/PKA signaling complex. To overcome the problem of ARMS-mediated TRPV1 sensitization by interaction, ARMS was silenced by shRNA. ARMS silencing resulted in a restored TRPV1 desensitization without affecting the TRPV1 expression and therefore could be used as new topical therapeutic analgesic alternative to stop ARMS mediated TRPV1 sensitization.},
language = {en}
}
@article{PerkinsRoseGrossartetal.2021,
author = {Perkins, Anita and Rose, Andrew and Grossart, Hans-Peter and Rojas-Jimenez, Keilor Osvaldo and Barroso Prescott, Selva Kiri and Oakes, Joanne M.},
title = {Oxic and Anoxic Organic Polymer Degradation Potential of Endophytic Fungi From the Marine Macroalga, Ecklonia radiata},
series = {Frontiers in Microbiology},
volume = {12},
journal = {Frontiers in Microbiology},
publisher = {Frontiers in microbiology},
address = {Lausanne, Schweiz},
issn = {1664-302X},
doi = {10.3389/fmicb.2021.726138},
pages = {1 -- 13},
year = {2021},
abstract = {Cellulose and chitin are the most abundant polymeric, organic carbon source globally. Thus, microbes degrading these polymers significantly influence global carbon cycling and greenhouse gas production. Fungi are recognized as important for cellulose decomposition in terrestrial environments, but are far less studied in marine environments, where bacterial organic matter degradation pathways tend to receive more attention. In this study, we investigated the potential of fungi to degrade kelp detritus, which is a major source of cellulose in marine systems. Given that kelp detritus can be transported considerable distances in the marine environment, we were specifically interested in the capability of endophytic fungi, which are transported with detritus, to ultimately contribute to kelp detritus degradation. We isolated 10 species and two strains of endophytic fungi from the kelp Ecklonia radiata. We then used a dye decolorization assay to assess their ability to degrade organic polymers (lignin, cellulose, and hemicellulose) under both oxic and anoxic conditions and compared their degradation ability with common terrestrial fungi. Under oxic conditions, there was evidence that Ascomycota isolates produced cellulose-degrading extracellular enzymes (associated with manganese peroxidase and sulfur-containing lignin peroxidase), while Mucoromycota isolates appeared to produce both lignin and cellulose-degrading extracellular enzymes, and all Basidiomycota isolates produced lignin-degrading enzymes (associated with laccase and lignin peroxidase). Under anoxic conditions, only three kelp endophytes degraded cellulose. We concluded that kelp fungal endophytes can contribute to cellulose degradation in both oxic and anoxic environments. Thus, endophytic kelp fungi may play a significant role in marine carbon cycling via polymeric organic matter degradation.},
language = {en}
}
@inproceedings{PoppBlaumDomptailetal.2006,
author = {Popp, Alexander and Blaum, Niels and Domptail, Stephanie and Herpel, Nicole and Gr{\"o}ngr{\"o}ft, Alexander and Hoffman, T. T. and J{\"u}rgens, Norbert and Milton, Sue and Nuppenau, Ernst-August and Rossmanith, Eva and Schmidt, Michael and Vogel, Melanie and Vohland, Katrin and Jeltsch, Florian},
title = {From satellite imagery to soil-plant interactions},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7302},
year = {2006},
abstract = {Decisions for the conservation of biodiversity and sustainable management of natural resources are typically related to large scales, i.e. the landscape level. However, understanding and predicting the effects of land use and climate change on scales relevant for decision-making requires to include both, large scale vegetation dynamics and small scale processes, such as soil-plant interactions. Integrating the results of multiple BIOTA subprojects enabled us to include necessary data of soil science, botany, socio-economics and remote sensing into a high resolution, process-based and spatially-explicit model. Using an example from a sustainably-used research farm and a communally used and degraded farming area in semiarid southern Namibia we show the power of simulation models as a tool to integrate processes across disciplines and scales.},
language = {en}
}
@article{RaatzPirhoferWalzlMuelleretal.2021,
author = {Raatz, Larissa and Pirhofer-Walzl, Karin and M{\"u}ller, Marina E.H. and Scherber, Christoph and Joshi, Jasmin Radha},
title = {Who is the culprit: Is pest infestation responsible for crop yield losses close to semi-natural habitats?},
series = {Ecology and Evolution},
volume = {11},
journal = {Ecology and Evolution},
edition = {19},
publisher = {Wiley-Blackwell},
address = {Oxford},
issn = {1467-6435},
doi = {10.1002/ece3.8046},
pages = {13232 -- 13246},
year = {2021},
abstract = {Semi-natural habitats (SNHs) are becoming increasingly scarce in modern agricultural landscapes. This may reduce natural ecosystem services such as pest control with its putatively positive effect on crop production. In agreement with other studies, we recently reported wheat yield reductions at field borders which were linked to the type of SNH and the distance to the border. In this experimental landscape-wide study, we asked whether these yield losses have a biotic origin while analyzing fungal seed and fungal leaf pathogens, herbivory of cereal leaf beetles, and weed cover as hypothesized mediators between SNHs and yield. We established experimental winter wheat plots of a single variety within conventionally managed wheat fields at fixed distances either to a hedgerow or to an in-field kettle hole. For each plot, we recorded the fungal infection rate on seeds, fungal infection and herbivory rates on leaves, and weed cover. Using several generalized linear mixed-effects models as well as a structural equation model, we tested the effects of SNHs at a field scale (SNH type and distance to SNH) and at a landscape scale (percentage and diversity of SNHs within a 1000-m radius). In the dry year of 2016, we detected one putative biotic culprit: Weed cover was negatively associated with yield values at a 1-m and 5-m distance from the field border with a SNH. None of the fungal and insect pests, however, significantly affected yield, neither solely nor depending on type of or distance to a SNH. However, the pest groups themselves responded differently to SNH at the field scale and at the landscape scale. Our findings highlight that crop losses at field borders may be caused by biotic culprits; however, their negative impact seems weak and is putatively reduced by conventional farming practices.},
language = {en}
}
@article{ReegStriglJeltsch2022,
author = {Reeg, Jette and Strigl, Lea and Jeltsch, Florian},
title = {Agricultural buffer zone thresholds to safeguard functional bee diversity},
series = {Ecology and Evolution},
volume = {12},
journal = {Ecology and Evolution},
edition = {3},
publisher = {Wiley Online Library},
address = {Hoboken, New Jersey, USA},
issn = {2045-7758},
doi = {10.1002/ece3.8748},
pages = {1 -- 17},
year = {2022},
abstract = {Wild bee species are important pollinators in agricultural landscapes. However, population decline was reported over the last decades and is still ongoing. While agricultural intensification is a major driver of the rapid loss of pollinating species, transition zones between arable fields and forest or grassland patches, i.e., agricultural buffer zones, are frequently mentioned as suitable mitigation measures to support wild bee populations and other pollinator species. Despite the reported general positive effect, it remains unclear which amount of buffer zones is needed to ensure a sustainable and permanent impact for enhancing bee diversity and abundance. To address this question at a pollinator community level, we implemented a process-based, spatially explicit simulation model of functional bee diversity dynamics in an agricultural landscape. More specifically, we introduced a variable amount of agricultural buffer zones (ABZs) at the transition of arable to grassland, or arable to forest patches to analyze the impact on bee functional diversity and functional richness. We focused our study on solitary bees in a typical agricultural area in the Northeast of Germany. Our results showed positive effects with at least 25\% of virtually implemented agricultural buffer zones. However, higher amounts of ABZs of at least 75\% should be considered to ensure a sufficient increase in Shannon diversity and decrease in quasi-extinction risks. These high amounts of ABZs represent effective conservation measures to safeguard the stability of pollination services provided by solitary bee species. As the model structure can be easily adapted to other mobile species in agricultural landscapes, our community approach offers the chance to compare the effectiveness of conservation measures also for other pollinator communities in future.},
language = {en}
}
@phdthesis{Robalo2018,
author = {Robalo, Jo{\~a}o Ramiro Alavedra Mendes},
title = {Investigating the role of fluorinated amino acids on protein structure and function using simulation},
school = {Universit{\"a}t Potsdam},
pages = {84},
year = {2018},
language = {en}
}
@phdthesis{Rolo2023,
author = {Rolo, David},
title = {Assembly of photosystem I in thylakoid membranes},
school = {Universit{\"a}t Potsdam},
pages = {177},
year = {2023},
abstract = {The light reactions of photosynthesis are carried out by a series of multiprotein complexes embedded in thylakoid membranes. Among them, photosystem I (PSI), acting as plastocyanin-ferderoxin oxidoreductase, catalyzes the final reaction. Together with light-harvesting antenna I, PSI forms a high-molecular-weight supercomplex of ~600 kDa, consisting of eighteen subunits and nearly two hundred co-factors. Assembly of the various components into a functional thylakoid membrane complex requires precise coordination, which is provided by the assembly machinery. Although this includes a small number of proteins (PSI assembly factors) that have been shown to play a role in the formation of PSI, the process as a whole, as well as the intricacy of its members, remains largely unexplored. In the present work, two approaches were used to find candidate PSI assembly factors. First, EnsembleNet was used to select proteins thought to be functionally related to known PSI assembly factors in Arabidopsis thaliana (approach I), and second, co-immunoprecipitation (Co-IP) of tagged PSI assembly factors in Nicotiana tabacum was performed (approach II). Here, the novel PSI assembly factors designated CO-EXPRESSED WITH PSI ASSEMBLY 1 (CEPA1) and Ycf4-INTERACTING PROTEIN 1 (Y4IP1) were identified. A. thaliana null mutants for CEPA1 and Y4IP1 showed a growth phenotype and pale leaves compared with the wild type. Biophysical experiments using pulse amplitude modulation (PAM) revealed insufficient electron transport on the PSII acceptor side. Biochemical analyses revealed that both CEPA1 and Y4IP1 are specifically involved in PSI accumulation in A. thaliana at the post-translational level but are not essential. Consistent with their roles as factors in the assembly of a thylakoid membrane protein complex, the two proteins localize to thylakoid membranes. Remarkably, cepa1 y4ip1 double mutants exhibited lethal phenotypes in early developmental stages under photoautotrophic growth. Finally, co-IP and native gel experiments supported a possible role for CEPA1 and Y4IP1 in mediating PSI assembly in conjunction with other PSI assembly factors (e.g., PPD1- and PSA3-CEPA1 and Ycf4-Y4IP1). The fact that CEPA1 and Y4IP1 are found exclusively in green algae and higher plants suggests eukaryote-specific functions. Although the specific mechanisms need further investigation, CEPA1 and Y4IP1 are two novel assembly factors that contribute to PSI formation.},
language = {en}
}
@inproceedings{RossmanithBlaumKeiletal.2006,
author = {Rossmanith, Eva and Blaum, Niels and Keil, Manfred and Langerwisch, F. and Meyer, Jork and Popp, Alexander and Schmidt, Michael and Schultz, Christoph and Schwager, Monika and Vogel, Melanie and Wasiolka, Bernd and Jeltsch, Florian},
title = {Scaling up local population dynamics to regional scales},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7320},
year = {2006},
abstract = {In semi-arid savannas, unsustainable land use can lead to degradation of entire landscapes, e.g. in the form of shrub encroachment. This leads to habitat loss and is assumed to reduce species diversity. In BIOTA phase 1, we investigated the effects of land use on population dynamics on farm scale. In phase 2 we scale up to consider the whole regional landscape consisting of a diverse mosaic of farms with different historic and present land use intensities. This mosaic creates a heterogeneous, dynamic pattern of structural diversity at a large spatial scale. Understanding how the region-wide dynamic land use pattern affects the abundance of animal and plant species requires the integration of processes on large as well as on small spatial scales. In our multidisciplinary approach, we integrate information from remote sensing, genetic and ecological field studies as well as small scale process models in a dynamic region-wide simulation tool.
Interdisziplin{\"a}res Zentrum f{\"u}r Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006.},
language = {en}
}
@article{RoeslerGasparatosHermanussenetal.2022,
author = {R{\"o}sler, Antonia and Gasparatos, Nikolaos and Hermanussen, Michael and Scheffler, Christiane},
title = {Practicability and user-friendliness of height measurements by proof of concept APP using Augmented Reality, in 22 healthy children},
series = {Human biology and public health},
volume = {2022},
journal = {Human biology and public health},
number = {2},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph2022.2.48},
pages = {9},
year = {2022},
abstract = {Background: Child growth is a dynamic process. When measured at short intervals, children's growth shows characteristic patterns that can be of great importance for clinical purposes. Objective: To study whether measuring height on a daily basis using an APP is practicable and user-friendly. Methods: Recruitment took place via Snowball Sampling. Thirteen out of 14 contacted families signed up for a study period of 12 weeks with altogether 22 healthy children aged 3 to 13 years (response rate 93\%). The study started with a visit to the family home for the setup of the measurement site, conventional height measuring and initial training of the new measurement process. Follow-up appointments were made at four, eight and 12 weeks. The children's height was measured at daily intervals at their family homes over a period of three months. Results: The parents altogether recorded 1704 height measurements and meticulously documented practicability and problems when using the device. A 93\% response rate in recruitment was achieved by maintaining a high motivation within the families. Contact with the principal investigator was permanently available, including open communication, personal training and attendance during the appointments at the family homes. Conclusion: Measuring height by photographic display is interesting for children and parents and can be used for height measurements at home. A positive response rate of 13 out of 14 families with altogether 22 children highlights feasible recruitment and the high convenience and user-friendliness of daily APP-supported height measurements. Daily APP measurements appear to be a promising new tool for longitudinal growth studies.},
language = {en}
}
@article{RoeslerSchefflerHermanussen2023,
author = {R{\"o}sler, Antonia and Scheffler, Christiane and Hermanussen, Michael},
title = {No evidence of growth impairment after forced migration in Polish school children after World War II},
series = {Human biology and public health},
volume = {1},
journal = {Human biology and public health},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph2023.1.68},
pages = {8},
year = {2023},
abstract = {Background: Migration is omnipresent. It can come hand in hand with emotional stress which is known to influence the growth of children. Objective: The aim of this study was to analyse whether type of migration (forced or voluntary) and the geographic direction had influenced the growth of Polish children after World War II. Sample and Methods: A sub dataset of 2,208 individuals between the ages of 2-20, created from data of the 2nd Polish Anthropological Survey carried out in 1966-1969, including anthropometrical data and social and demographic information based on questionnaire, was used to analyse migration effects. Results: No association could be found between the direction of migration and the height of the children. The confidence intervals of the means of all classified migration categories overlap significantly and the effect size of the influence of migration category on height is ds=.140, which is too low to see any effects, even if there were one. Conclusion: Neither forced nor voluntary migration in Poland after World War II led to a change in height in children of migrating families.},
language = {en}
}
@phdthesis{Schauer2006,
author = {Schauer, Nicolas},
title = {Quantitative trait loci (QTL) for metabolite accumulation and metabolic regulation : metabolite profiling of interspecific crosses of tomato},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7643},
school = {Universit{\"a}t Potsdam},
year = {2006},
abstract = {The advent of large-scale and high-throughput technologies has recently caused a shift in focus in contemporary biology from decades of reductionism towards a more systemic view. Alongside the availability of genome sequences the exploration of organisms utilizing such approach should give rise to a more comprehensive understanding of complex systems. Domestication and intensive breeding of crop plants has led to a parallel narrowing of their genetic basis. The potential to improve crops by conventional breeding using elite cultivars is therefore rather limited and molecular technologies, such as marker assisted selection (MAS) are currently being exploited to re-introduce allelic variance from wild species. Molecular breeding strategies have mostly focused on the introduction of yield or resistance related traits to date. However given that medical research has highlighted the importance of crop compositional quality in the human diet this research field is rapidly becoming more important. Chemical composition of biological tissues can be efficiently assessed by metabolite profiling techniques, which allow the multivariate detection of metabolites of a given biological sample. Here, a GC/MS metabolite profiling approach has been applied to investigate natural variation of tomatoes with respect to the chemical composition of their fruits. The establishment of a mass spectral and retention index (MSRI) library was a prerequisite for this work in order to establish a framework for the identification of metabolites from a complex mixture. As mass spectral and retention index information is highly important for the metabolomics community this library was made publicly available. Metabolite profiling of tomato wild species revealed large differences in the chemical composition, especially of amino and organic acids, as well as on the sugar composition and secondary metabolites. Intriguingly, the analysis of a set of S. pennellii introgression lines (IL) identified 889 quantitative trait loci of compositional quality and 326 yield-associated traits. These traits are characterized by increases/decreases not only of single metabolites but also of entire metabolic pathways, thus highlighting the potential of this approach in uncovering novel aspects of metabolic regulation. Finally the biosynthetic pathway of the phenylalanine-derived fruit volatiles phenylethanol and phenylacetaldehyde was elucidated via a combination of metabolic profiling of natural variation, stable isotope tracer experiments and reverse genetic experimentation.},
subject = {Tomate},
language = {en}
}
@article{SchefflerHermanussen2023,
author = {Scheffler, Christiane and Hermanussen, Michael},
title = {What does stunting tell us?},
series = {Human biology and public health},
volume = {2022},
journal = {Human biology and public health},
number = {3},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph2022.3.36},
pages = {1 -- 15},
year = {2023},
abstract = {Stunting is commonly linked with undernutrition. Yet, already after World War I, German pediatricians questioned this link and stated that no association exists between nutrition and height. Recent analyses within different populations of Low- and middle-income countries with high rates of stunted children failed to support the assumption that stunted children have a low BMI and skinfold sickness as signs of severe caloric deficiency. So, stunting is not a synonym of malnutrition. Parental education level has a positive influence on body height in stunted populations, e.g., in India and in Indonesia. Socially disadvantaged children tend to be shorter and lighter than children from affluent families. Humans are social mammals; they regulate growth similar to other social mammals. Also in humans, body height is strongly associated with the position within the social hierarchy, reflecting the personal and group-specific social, economic, political, and emotional environment. These non-nutritional impact factors on growth are summarized by the concept of SEPE (Social-Economic-Political-Emotional) factors. SEPE reflects on prestige, dominance-subordination, social identity, and ego motivation of individuals and social groups.},
language = {en}
}
@article{SchefflerHermanussen2021,
author = {Scheffler, Christiane and Hermanussen, Michael},
title = {Stunting does not impair physical fitness in Indonesian school children},
series = {Human biology and public health},
journal = {Human biology and public health},
number = {2},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph.v2.19},
year = {2021},
abstract = {Background: Physical fitness is decreased in malnourished children and adults. Poor appearance and muscular flaccidity are among the first signs of malnutrition. Malnutrition is often associated with stunting. Objectives: We test the hypotheses that stunted children of low social strata are physically less fit than children of high social strata. Sample: We investigated 354 school girls and 369 school boys aged 5.83 to 13.83 (mean 9.54) years from three different social strata in Kupang (West-Timor, Indonesia) in 2020. Methods: We measured height, weight, and elbow breadth, calculated standard deviation (SDS) of height and weight according to CDC references, and the Frame index as an indicator of long-term physical fitness, and we tested physical fitness in standing long jump and hand grip strength. Results: Children of low social strata are physically fittest. They jump longer distances, and they have higher values in the Frame index. No association exists between height SDS and physical fitness, neither in respect to standing long jump, nor to hand grip strength. Conclusion: Stunting does not impair physical fitness in Indonesian school children. Our results support the concept that SEPE (social-economic-political-emotional) factors are involved in the regulation of human growth.},
language = {en}
}
@article{SchefflerNguyenHermanussen2021,
author = {Scheffler, Christiane and Nguyen, Thi Hong and Hermanussen, Michael},
title = {Vietnamese migrants are as tall as they want to be},
series = {Human biology and public health},
journal = {Human biology and public health},
number = {2},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph.v2.12},
year = {2021},
abstract = {Background: Members of the same social group tent to have the same body height. Migrants tend to adjust in height to their host communities. Objectives: Social-Economic-Political-Emotional (SEPE) factors influence growth. We hypothesized that Vietnamese young adult migrants in Germany (1) are taller than their parents, (2) are as tall as their German peers, and (3) are as tall as predicted by height expectation at age 13 years. Sample: The study was conducted in 30 male and 54 female Vietnamese migrants (mean age 26.23 years. SD=4.96) in Germany in 2020. Methods: Information on age, sex, body height, school and education, job, height and ethnicity of best friend, migration history and cultural identification, parental height and education, and recalled information on their personal height expectations at age 13 years were obtained by questionnaire. The data were analyzed by St. Nicolas House Analysis (SNHA) and multiple regression. Results: Vietnamese young adults are taller than their parents (females 3.85cm, males 7.44cm), but do not fully attain height of their German peers. The body height is positively associated with the height of best friend (p < 0.001), the height expectation at age 13 year (p < 0.001), and father's height (p=0.001). Conclusion: Body height of Vietnamese migrants in Germany reflects competitive growth and strategic growth adjustments. The magnitude of this intergenerational trend supports the concept that human growth depends on SEPE factors.},
language = {en}
}
@article{SchefflerRogolIancuetal.2021,
author = {Scheffler, Christiane and Rogol, Alan D. and Iancu, Mirela and Hanc, Tomasz and Moelyo, Annang Giri and Suchomlinov, Andrej and Lebedeva, Lidia and Limony, Yehuda and Musalek, Martin and Veldre, Gudrun and Godina, Elena Z. and Kirchengast, Sylvia and Mumm, Rebekka and Groth, Detlef and Tutkuviene, Janina and B{\"o}ker, Sonja and Ozer, Basak Koca and Navazo, Barbara and Spake, Laure and Koziel, Slawomir and Hermanussen, Michael},
title = {Growth during times of fear and emotional stress},
series = {Human biology and public health},
journal = {Human biology and public health},
number = {2},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {2748-9957},
doi = {10.52905/hbph.v2.15},
year = {2021},
abstract = {Twenty-one scientists met for this year's virtual conference on Auxology held at the University Potsdam, Germany, to discuss child and adolescent growth during times of fear and emotional stress. Growth within the broad range of normal for age and sex is considered a sign of good general health whereas fear and emotional stress can lead to growth faltering. Stunting is a sign of social disadvantage and poor parental education. Adverse childhood experiences affect child development, particularly in families with low parental education and low socioeconomic status. Negative effects were also shown in Indian children exposed prenatally and in early postnatal life to the cyclone Aila in 2009. Distrust, fears and fake news regarding the current Corona pandemic received particular attention though the effects generally appeared weak. Mean birth weight was higher; rates of low, very and extremely low birth weight were lower. Other topics discussed by the participants, were the influences of economic crises on birth weight, the measurement of self-confidence and its impact on growth, the associations between obesity, peer relationship, and behavior among Turkish adolescents, height trends in Indonesia, physiological neonatal weight loss, methods for assessing biological maturation in sportsmen, and a new method for skeletal age determination. The participants also discussed the association between acute myocardial infarction and somatotype in Estonia, rural-urban growth differences in Mongolian children, socio-environmental conditions and sexual dimorphism, biological mortality bias, and new statistical techniques for describing inhomogeneity in the association of bivariate variables, and for detecting and visualizing extensive interactions among variables.},
language = {en}
}
@article{SchloerHirschbergBenAmoretal.2022,
author = {Schl{\"o}r, Anja and Hirschberg, Stefan and Ben Amor, Ghada and Meister, Toni Luise and Arora, Prerna and P{\"o}hlmann, Stefan and Hoffmann, Markus and Pf{\"a}nder, Stephanie and Eddin, Omar Kamal and Kamhieh-Milz, Julian and Hanack, Katja},
title = {SARS-CoV-2 neutralizing camelid heavy-chain-only antibodies as powerful tools for diagnostic and therapeutic applications},
series = {Frontiers in Immunology},
journal = {Frontiers in Immunology},
publisher = {Frontiers Media SA},
address = {Lausanne, Schweiz},
issn = {1664-3224},
doi = {10.3389/fimmu.2022.930975},
pages = {1 -- 14},
year = {2022},
abstract = {Introduction: The ongoing COVID-19 pandemic situation caused by SARS-CoV-2 and variants of concern such as B.1.617.2 (Delta) and recently, B.1.1.529 (Omicron) is posing multiple challenges to humanity. The rapid evolution of the virus requires adaptation of diagnostic and therapeutic applications. Objectives: In this study, we describe camelid heavy-chain-only antibodies (hcAb) as useful tools for novel in vitro diagnostic assays and for therapeutic applications due to their neutralizing capacity. Methods: Five antibody candidates were selected out of a na{\"i}ve camelid library by phage display and expressed as full length IgG2 antibodies. The antibodies were characterized by Western blot, enzyme-linked immunosorbent assays, surface plasmon resonance with regard to their specificity to the recombinant SARS-CoV-2 Spike protein and to SARS-CoV-2 virus-like particles. Neutralization assays were performed with authentic SARS-CoV-2 and pseudotyped viruses (wildtype and Omicron). Results: All antibodies efficiently detect recombinant SARS-CoV-2 Spike protein and SARS-CoV-2 virus-like particles in different ELISA setups. The best combination was shown with hcAb B10 as catcher antibody and HRP-conjugated hcAb A7.2 as the detection antibody. Further, four out of five antibodies potently neutralized authentic wildtype SARS-CoV-2 and particles pseudotyped with the SARS-CoV-2 Spike proteins of the wildtype and Omicron variant, sublineage BA.1 at concentrations between 0.1 and 0.35 ng/mL (ND50). Conclusion: Collectively, we report novel camelid hcAbs suitable for diagnostics and potential therapy.},
language = {en}
}
@phdthesis{Schuette2011,
author = {Sch{\"u}tte, Moritz},
title = {Evolutionary fingerprints in genome-scale networks},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57483},
school = {Universit{\"a}t Potsdam},
year = {2011},
abstract = {Mathematical modeling of biological phenomena has experienced increasing interest since new high-throughput technologies give access to growing amounts of molecular data. These modeling approaches are especially able to test hypotheses which are not yet experimentally accessible or guide an experimental setup. One particular attempt investigates the evolutionary dynamics responsible for today's composition of organisms. Computer simulations either propose an evolutionary mechanism and thus reproduce a recent finding or rebuild an evolutionary process in order to learn about its mechanism. The quest for evolutionary fingerprints in metabolic and gene-coexpression networks is the central topic of this cumulative thesis based on four published articles. An understanding of the actual origin of life will probably remain an insoluble problem. However, one can argue that after a first simple metabolism has evolved, the further evolution of metabolism occurred in parallel with the evolution of the sequences of the catalyzing enzymes. Indications of such a coevolution can be found when correlating the change in sequence between two enzymes with their distance on the metabolic network which is obtained from the KEGG database. We observe that there exists a small but significant correlation primarily on nearest neighbors. This indicates that enzymes catalyzing subsequent reactions tend to be descended from the same precursor. Since this correlation is relatively small one can at least assume that, if new enzymes are no "genetic children" of the previous enzymes, they certainly be descended from any of the already existing ones. Following this hypothesis, we introduce a model of enzyme-pathway coevolution. By iteratively adding enzymes, this model explores the metabolic network in a manner similar to diffusion. With implementation of an Gillespie-like algorithm we are able to introduce a tunable parameter that controls the weight of sequence similarity when choosing a new enzyme. Furthermore, this method also defines a time difference between successive evolutionary innovations in terms of a new enzyme. Overall, these simulations generate putative time-courses of the evolutionary walk on the metabolic network. By a time-series analysis, we find that the acquisition of new enzymes appears in bursts which are pronounced when the influence of the sequence similarity is higher. This behavior strongly resembles punctuated equilibrium which denotes the observation that new species tend to appear in bursts as well rather than in a gradual manner. Thus, our model helps to establish a better understanding of punctuated equilibrium giving a potential description at molecular level. From the time-courses we also extract a tentative order of new enzymes, metabolites, and even organisms. The consistence of this order with previous findings provides evidence for the validity of our approach. While the sequence of a gene is actually subject to mutations, its expression profile might also indirectly change through the evolutionary events in the cellular interplay. Gene coexpression data is simply accessible by microarray experiments and commonly illustrated using coexpression networks where genes are nodes and get linked once they show a significant coexpression. Since the large number of genes makes an illustration of the entire coexpression network difficult, clustering helps to show the network on a metalevel. Various clustering techniques already exist. However, we introduce a novel one which maintains control of the cluster sizes and thus assures proper visual inspection. An application of the method on Arabidopsis thaliana reveals that genes causing a severe phenotype often show a functional uniqueness in their network vicinity. This leads to 20 genes of so far unknown phenotype which are however suggested to be essential for plant growth. Of these, six indeed provoke such a severe phenotype, shown by mutant analysis. By an inspection of the degree distribution of the A.thaliana coexpression network, we identified two characteristics. The distribution deviates from the frequently observed power-law by a sharp truncation which follows after an over-representation of highly connected nodes. For a better understanding, we developed an evolutionary model which mimics the growth of a coexpression network by gene duplication which underlies a strong selection criterion, and slight mutational changes in the expression profile. Despite the simplicity of our assumption, we can reproduce the observed properties in A.thaliana as well as in E.coli and S.cerevisiae. The over-representation of high-degree nodes could be identified with mutually well connected genes of similar functional families: zinc fingers (PF00096), flagella, and ribosomes respectively. In conclusion, these four manuscripts demonstrate the usefulness of mathematical models and statistical tools as a source of new biological insight. While the clustering approach of gene coexpression data leads to the phenotypic characterization of so far unknown genes and thus supports genome annotation, our model approaches offer explanations for observed properties of the coexpression network and furthermore substantiate punctuated equilibrium as an evolutionary process by a deeper understanding of an underlying molecular mechanism.},
language = {en}
}
@phdthesis{Senger2007,
author = {Senger, Toralf},
title = {Untersuchungen zur Metallhom{\"o}ostase in Arabidopsis thaliana},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13234},
school = {Universit{\"a}t Potsdam},
year = {2007},
abstract = {Alle Organismen sind f{\"u}r ihr {\"U}berleben auf Metalle angewiesen. Hierbei gibt es f{\"u}r jedes Metall einen Konzentrationsbereich, der das Optimum zwischen Metallmangel, -bedarf und -toxizit{\"a}t darstellt. Es gilt mittlerweile als erwiesen, dass alle Organismen zur Aufrechterhaltung des Metallgleichgewichts ein komplexes Netzwerk von Proteinen und niedermolekularen Verbindungen entwickelt haben. Die molekularen Komponenten dieses Netzwerks sind nur zu einem Teil bekannt und charakterisiert: In den letzten Jahren wurden einige Proteinfamilien identifiziert, deren Mitglieder Metalle durch Lipidmembranen transportieren. Eine dieser Metalltransporterfamilien ist die Cation Diffusion Facilitator (CDF)-Familie: Alle charakterisierten Mitglieder exportieren Metalle aus dem Zytoplasma - entweder in zellul{\"a}re Kompartimente oder aus der Zelle heraus. Von den zw{\"o}lf Mitgliedern dieser Familie in Arabidopsis thaliana (A. thaliana) - Metall Toleranz Protein (MTP)-1 bis -12 - wurden bisher AtMTP1 und AtMTP3 charakterisiert. In dieser Arbeit wird die Charakterisierung von AtMTP2 beschrieben. Wie die homologen Proteine AtMTP1 und AtMTP3 f{\"u}hrt AtMTP2 zu Zn-Toleranz, wenn es heterolog in Zn-sensitiven Hefemutanten exprimiert wird. Mit AtMTP2 transformierte Hefemutanten zeigten dar{\"u}ber hinaus erh{\"o}hte Co-Toleranz. Expression von chim{\"a}ren AtMTP2/GFP Fusionsproteinen in Hefe, A.thaliana protoplasten und in stabil transformierten A.thalinana Planzenlinien deutet auf Lokalisation of AtMTP2 in Membranen des Endoplasmatischen Retikulums (ER) hin, wenn GFP an den C-Terminus von MTP2 fusioniert wird. Fusion of GFP an den N-Terminus von AtMTP2 f{\"u}hrte zu Lokalisation in der vakuol{\"a}ren Membran, was wahrscheinlichsten auf Fehllokalisierung durch Maskierung eines ER-Retentionsmotivs (XXRR) am N-Terminus von AtMTP2 zur{\"u}ckgeht. Dies legt nahe, dass AtMTP2 die erw{\"a}hnten Metalle in das Endomembransystem der Zelle transportieren kann. Eine gewebespezifische Lokalisierung wurde mit Pflanzen durchgef{\"u}hrt, die das β-Glucuronidase (GUS)-Reporterprotein bzw. chim{\"a}re Fusionsproteine aus EGFP und AtMTP2 unter Kontrolle des nativen pMTP2-Promotors exprimierten. Diese Experimente best{\"a}tigten zum einen, dass der pMTP2-Promotor nur unter Zn-Defizienz aktiv ist. GUS-Aktivit{\"a}t wurde unter diesen Bedingungen in zwei Zonen der Wurzelspitze beobachtet: in den isodiametrischen Zellen der meristematischen Zone und in der beginnenden Wurzelhaarzone. Dar{\"u}ber hinaus konnte gezeigt werden, dass die EGFP-Fusionsproteine unter Kontrolle des nativen pMTP2-Promotors nur in epidermalen Zellen exprimiert werden. F{\"u}r eine homozygote Knockout- Linie, mtp2-S3, konnte bisher kein eindeutiger Ph{\"a}notyp identifiziert werden. Auf Grundlage der bisher durchgef{\"u}hrten Charakterisierung von AtMTP2 erscheinen zwei Modelle der Funktion von AtMTP2 in der Pflanze m{\"o}glich: AtMTP2 k{\"o}nnte essentiell f{\"u}r die Versorgung des ER mit Zn unter Zn-Mangelbedingungen sein. Hierf{\"u}r spricht, dass AtMTP2 in jungen, teilungsaktiven und damit Zn-ben{\"o}tigenden Wurzelzonen exprimiert wird. Die auf die Epidermis beschr{\"a}nkte Lokalisation k{\"o}nnte bei diesem Modell auf die M{\"o}glichkeit der zwischenzellul{\"a}ren Zn-Verteilung innerhalb des ER {\"u}ber Desmotubules hindeuten. Alternativ k{\"o}nnte AtMTP2 eine Funktion bei der Detoxifizierung von Zn unter Zn-Schock Bedingungen haben: Es ist bekannt, dass unter Zn- Mangelbedingungen die Expression der zellul{\"a}ren Zn-Aufnahmesysteme hochreguliert wird. Wenn nun die Zn-Verf{\"u}gbarkeit im Boden z. B durch eine pH-{\"A}nderung innerhalb kurzer Zeit stark ansteigt, besteht die Notwendigkeit der Entgiftung von Zn innerhalb der Zelle, bis der starke Einstrom von Zn ins Zytoplasma durch die Deaktivierung der Zn-Aufnahmesysteme und einer geringeren Expression in der Pflanze gedrosselt ist. Ein {\"a}hnlicher Mechanismus wurde in der B{\"a}ckerhefe S. cerevisae beschrieben, in der dar{\"u}ber hinaus ein Zn-Transporter verst{\"a}rkt exprimiert wird, der Zn durch Transport in die Vakuole entgiften kann. Es ist durchaus m{\"o}glich, dass in Arabidopsis AtMTP2 die Zn-Detoxifizierung unter diesen speziellen Bedingungen durch Zn-Transport in das ER oder die Vakuole vermittelt. Zur Identifikation weiterer Komponenten des Metallhom{\"o}ostasenetzwerks sind verschiedene Ans{\"a}tze denkbar. In dieser Arbeit wurde in Hefe ein heterologer Screen durchgef{\"u}hrt, um Interaktoren f{\"u}r vier Mitglieder der Arabidopsis-CDF-Familie zu identifizieren. Unter den 11 im Hefesystem best{\"a}tigten Kandidaten befindet sich mit AtSPL1 ein AtMTP1-Interaktionskandidat, der m{\"o}glicherweise eine Rolle bei der Cu-,Zn-Hom{\"o}ostase spielt. Als wahrscheinliche AtMTP3-Interaktionskandidaten wurde die c"-Untereinheit der vakuol{\"a}ren H+-ATPase AtVHA identifiziert sowie mit AtNPSN13 ein Protein, das vermutlich eine Rolle bei Fusionen von Vesikeln mit Zielmembranen spielt. Ein anderer Ansatz zur Identifikation neuer Metallhom{\"o}ostasegene ist die vergleichende Elementanalyse von nat{\"u}rlichen oder mutagenisierten Pflanzenpopulationen. Voraussetzung f{\"u}r diesen Ansatz ist die schnelle und genaue Analyse des Elementgehalts von Pflanzen. Eine etablierte Methode zur simultanen Bestimmung von bis zu 65 Elementen in einer Probe ist die Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES). Der limitierende Faktor f{\"u}r einen hohen Probendurchsatz ist die Notwendigkeit, Proben f{\"u}r die Analyse zu verfl{\"u}ssigen. Eine alternative Methode der Probenzuf{\"u}hrung zum Analyseger{\"a}t ist die elektrothermale Verdampfung (ETV) der Probe. Zur weitgehend automatisierten Analyse von Pflanzenmaterial mit minimiertem Arbeitsaufwand wurde eine Methode entwickelt, die auf der Kopplung der ETV mit der ICP OES basiert.},
language = {de}
}
@article{SpikesRodriguezSilvaBennettetal.2021,
author = {Spikes, Montrai and Rodr{\´i}guez-Silva, Rodet and Bennett, Kerri-Ann and Br{\"a}ger, Stefan and Josaphat, James and Torres-Pineda, Patricia and Ernst, Anja and Havenstein, Katja and Schlupp, Ingo and Tiedemann, Ralph},
title = {A phylogeny of the genus Limia (Teleostei: Poeciliidae) suggests a single-lake radiation nested in a Caribbean-wide allopatric speciation scenario},
series = {BMC Research Notes},
volume = {14},
journal = {BMC Research Notes},
publisher = {BMC Research Notes / Biomed Central},
address = {London},
issn = {1756-0500},
doi = {10.1186/s13104-021-05843-x},
pages = {1 -- 8},
year = {2021},
abstract = {Objective The Caribbean is an important global biodiversity hotspot. Adaptive radiations there lead to many speciation events within a limited period and hence are particularly prominent biodiversity generators. A prime example are freshwater fish of the genus Limia, endemic to the Greater Antilles. Within Hispaniola, nine species have been described from a single isolated site, Lake Mirago{\^a}ne, pointing towards extraordinary sympatric speciation. This study examines the evolutionary history of the Limia species in Lake Mirago{\^a}ne, relative to their congeners throughout the Caribbean. Results For 12 Limia species, we obtained almost complete sequences of the mitochondrial cytochrome b gene, a well-established marker for lower-level taxonomic relationships. We included sequences of six further Limia species from GenBank (total N = 18 species). Our phylogenies are in concordance with other published phylogenies of Limia. There is strong support that the species found in Lake Mirago{\^a}ne in Haiti are monophyletic, confirming a recent local radiation. Within Lake Mirago{\^a}ne, speciation is likely extremely recent, leading to incomplete lineage sorting in the mtDNA. Future studies using multiple unlinked genetic markers are needed to disentangle the relationships within the Lake Mirago{\^a}ne clade.},
language = {en}
}
@phdthesis{Stanke2023,
author = {Stanke, Sandra},
title = {AC electrokinetic immobilization of influenza viruses and antibodies on nanoelectrode arrays for on-chip immunoassays},
doi = {10.25932/publishup-61716},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-617165},
school = {Universit{\"a}t Potsdam},
pages = {x, 115},
year = {2023},
abstract = {In the present thesis, AC electrokinetic forces, like dielectrophoresis and AC electroosmosis, were demonstrated as a simple and fast method to functionalize the surface of nanoelectrodes with submicrometer sized biological objects. These nanoelectrodes have a cylindrical shape with a diameter of 500 nm arranged in an array of 6256 electrodes. Due to its medical relevance influenza virus as well as anti-influenza antibodies were chosen as a model organism. Common methods to bring antibodies or proteins to biosensor surfaces are complex and time-consuming. In the present work, it was demonstrated that by applying AC electric fields influenza viruses and antibodies can be immobilized onto the nanoelectrodes within seconds without any prior chemical modification of neither the surface nor the immobilized biological object. The distribution of these immobilized objects is not uniform over the entire array, it exhibits a decreasing gradient from the outer row to the inner ones. Different causes for this gradient have been discussed, such as the vortex-shaped fluid motion above the nanoelectrodes generated by, among others, electrothermal fluid flow. It was demonstrated that parts of the accumulated material are permanently immobilized to the electrodes. This is a unique characteristic of the presented system since in the literature the AC electrokinetic immobilization is almost entirely presented as a method just for temporary immobilization. The spatial distribution of the immobilized viral material or the anti-influenza antibodies at the electrodes was observed by either the combination of fluorescence microscopy and deconvolution or by super-resolution microscopy (STED). On-chip immunoassays were performed to examine the suitability of the functionalized electrodes as a potential affinity-based biosensor. Two approaches were pursued: A) the influenza virus as the bio-receptor or B) the influenza virus as the analyte. Different sources of error were eliminated by ELISA and passivation experiments. Hence, the activity of the immobilized object was inspected by incubation with the analyte. This resulted in the successful detection of anti-influenza antibodies by the immobilized viral material. On the other hand, a detection of influenza virus particles by the immobilized anti-influenza antibodies was not possible. The latter might be due to lost activity or wrong orientation of the antibodies. Thus, further examinations on the activity of by AC electric fields immobilized antibodies should follow. When combined with microfluidics and an electrical read-out system, the functionalized chips possess the potential to serve as a rapid, portable, and cost-effective point-of-care (POC) device. This device can be utilized as a basis for diverse applications in diagnosing and treating influenza, as well as various other pathogens.},
language = {en}
}
@misc{SteinfathGaertnerLisecetal.2009,
author = {Steinfath, Matthias and G{\"a}rtner, Tanja and Lisec, Jan and Meyer, Rhonda C. and Altmann, Thomas and Willmitzer, Lothar and Selbig, Joachim},
title = {Prediction of hybrid biomass in Arabidopsis thaliana by selected parental SNP and metabolic markers},
series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
number = {1324},
issn = {1866-8372},
doi = {10.25932/publishup-43111},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431115},
pages = {9},
year = {2009},
abstract = {A recombinant inbred line (RIL) population, derived from two Arabidopsis thaliana accessions, and the corresponding testcrosses with these two original accessions were used for the development and validation of machine learning models to predict the biomass of hybrids. Genetic and metabolic information of the RILs served as predictors. Feature selection reduced the number of variables (genetic and metabolic markers) in the models by more than 80\% without impairing the predictive power. Thus, potential biomarkers have been revealed. Metabolites were shown to bear information on inherited macroscopic phenotypes. This proof of concept could be interesting for breeders. The example population exhibits substantial mid-parent biomass heterosis. The results of feature selection could therefore be used to shed light on the origin of heterosis. In this respect, mainly dominance effects were detected.},
language = {en}
}
@article{SteinfathGaertnerLisecetal.2009,
author = {Steinfath, Matthias and G{\"a}rtner, Tanja and Lisec, Jan and Meyer, Rhonda Christiane and Altmann, Thomas and Willmitzer, Lothar and Selbig, Joachim},
title = {Prediction of hybrid biomass in Arabidopsis thaliana by selected parental SNP and metabolic markers},
series = {Theoretical and applied genetics : TAG ; international journal of plant breeding research},
volume = {120},
journal = {Theoretical and applied genetics : TAG ; international journal of plant breeding research},
publisher = {Springer},
address = {Berlin},
issn = {0040-5752},
doi = {10.1007/s00122-009-1191-2},
pages = {239 -- 247},
year = {2009},
abstract = {A recombinant inbred line (RIL) population, derived from two Arabidopsis thaliana accessions, and the corresponding testcrosses with these two original accessions were used for the development and validation of machine learning models to predict the biomass of hybrids. Genetic and metabolic information of the RILs served as predictors. Feature selection reduced the number of variables (genetic and metabolic markers) in the models by more than 80\% without impairing the predictive power. Thus, potential biomarkers have been revealed. Metabolites were shown to bear information on inherited macroscopic phenotypes. This proof of concept could be interesting for breeders. The example population exhibits substantial mid-parent biomass heterosis. The results of feature selection could therefore be used to shed light on the origin of heterosis. In this respect, mainly dominance effects were detected.},
language = {en}
}
@misc{StieglerLinsDammhahnetal.2022,
author = {Stiegler, Jonas and Lins, Alisa and Dammhahn, Melanie and Kramer-Schadt, Stephanie and Ortmann, Sylvia and Blaum, Niels},
title = {Personality drives activity and space use in a mammalian herbivore},
series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
publisher = {Universit{\"a}tsverlag Potsdam},
address = {Potsdam},
issn = {1866-8372},
doi = {10.25932/publishup-57732},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-577327},
pages = {1 -- 12},
year = {2022},
abstract = {Background Animal personality has emerged as a key concept in behavioral ecology. While many studies have demonstrated the influence of personality traits on behavioral patterns, its quantification, especially in wild animal populations, remains a challenge. Only a few studies have established a link between personality and recurring movements within home ranges, although these small-scale movements are of key importance for identifying ecological interactions and forming individual niches. In this regard, differences in space use among individuals might reflect different exploration styles between behavioral types along the shy-bold continuum. Methods We assessed among-individual differences in behavior in the European hare (Lepus europaeus), a characteristic mammalian herbivore in agricultural landscapes using a standardized box emergence test for captive and wild hares. We determined an individuals' degree of boldness by measuring the latencies of behavioral responses in repeated emergence tests in captivity. During capture events of wild hares, we conducted a single emergence test and recorded behavioral responses proven to be stable over time in captive hares. Applying repeated novel environment tests in a near-natural enclosure, we further quantified aspects of exploration and activity in captive hares. Finally, we investigated whether and how this among-individual behavioral variation is related to general activity and space use in a wild hare population. Wild and captive hares were treated similarly and GPS-collared with internal accelerometers prior to release to the wild or the outdoor enclosure, respectively. General activity was quantified as overall dynamic body acceleration (ODBA) obtained from accelerometers. Finally, we tested whether boldness explained variation in (i) ODBA in both settings and (ii) variation in home ranges and core areas across different time scales of GPS-collared hares in a wild population. Results We found three behavioral responses to be consistent over time in captive hares. ODBA was positively related to boldness (i.e., short latencies to make first contact with the new environment) in both captive and wild hares. Space use in wild hares also varied with boldness, with shy individuals having smaller core areas and larger home ranges than bold conspecifics (yet in some of the parameter space, this association was just marginally significant). Conclusions Against our prediction, shy individuals occupied relatively large home ranges but with small core areas. We suggest that this space use pattern is due to them avoiding risky, and energy-demanding competition for valuable resources. Carefully validated, activity measurements (ODBA) from accelerometers provide a valuable tool to quantify aspects of animal personality along the shy-bold continuum remotely. Without directly observing—and possibly disturbing—focal individuals, this approach allows measuring variability in animal personality, especially in species that are difficult to assess with experiments. Considering that accelerometers are often already built into GPS units, we recommend activating them at least during the initial days of tracking to estimate individual variation in general activity and, if possible, match them with a simple novelty experiment. Furthermore, information on individual behavioral types will help to facilitate mechanistic understanding of processes that drive spatial and ecological dynamics in heterogeneous landscapes.},
language = {en}
}
@article{StieglerLinsDammhahnetal.2022,
author = {Stiegler, Jonas and Lins, Alisa and Dammhahn, Melanie and Kramer-Schadt, Stephanie and Ortmann, Sylvia and Blaum, Niels},
title = {Personality drives activity and space use in a mammalian herbivore},
series = {Movement Ecology},
volume = {10},
journal = {Movement Ecology},
publisher = {BioMed Central (BMC), Springer Nature},
address = {London},
issn = {2051-3933},
doi = {10.1186/s40462-022-00333-6},
pages = {12},
year = {2022},
abstract = {Background Animal personality has emerged as a key concept in behavioral ecology. While many studies have demonstrated the influence of personality traits on behavioral patterns, its quantification, especially in wild animal populations, remains a challenge. Only a few studies have established a link between personality and recurring movements within home ranges, although these small-scale movements are of key importance for identifying ecological interactions and forming individual niches. In this regard, differences in space use among individuals might reflect different exploration styles between behavioral types along the shy-bold continuum. Methods We assessed among-individual differences in behavior in the European hare (Lepus europaeus), a characteristic mammalian herbivore in agricultural landscapes using a standardized box emergence test for captive and wild hares. We determined an individuals' degree of boldness by measuring the latencies of behavioral responses in repeated emergence tests in captivity. During capture events of wild hares, we conducted a single emergence test and recorded behavioral responses proven to be stable over time in captive hares. Applying repeated novel environment tests in a near-natural enclosure, we further quantified aspects of exploration and activity in captive hares. Finally, we investigated whether and how this among-individual behavioral variation is related to general activity and space use in a wild hare population. Wild and captive hares were treated similarly and GPS-collared with internal accelerometers prior to release to the wild or the outdoor enclosure, respectively. General activity was quantified as overall dynamic body acceleration (ODBA) obtained from accelerometers. Finally, we tested whether boldness explained variation in (i) ODBA in both settings and (ii) variation in home ranges and core areas across different time scales of GPS-collared hares in a wild population. Results We found three behavioral responses to be consistent over time in captive hares. ODBA was positively related to boldness (i.e., short latencies to make first contact with the new environment) in both captive and wild hares. Space use in wild hares also varied with boldness, with shy individuals having smaller core areas and larger home ranges than bold conspecifics (yet in some of the parameter space, this association was just marginally significant). Conclusions Against our prediction, shy individuals occupied relatively large home ranges but with small core areas. We suggest that this space use pattern is due to them avoiding risky, and energy-demanding competition for valuable resources. Carefully validated, activity measurements (ODBA) from accelerometers provide a valuable tool to quantify aspects of animal personality along the shy-bold continuum remotely. Without directly observing—and possibly disturbing—focal individuals, this approach allows measuring variability in animal personality, especially in species that are difficult to assess with experiments. Considering that accelerometers are often already built into GPS units, we recommend activating them at least during the initial days of tracking to estimate individual variation in general activity and, if possible, match them with a simple novelty experiment. Furthermore, information on individual behavioral types will help to facilitate mechanistic understanding of processes that drive spatial and ecological dynamics in heterogeneous landscapes.},
language = {en}
}
@phdthesis{Swart2017,
author = {Swart, Corn{\´e}},
title = {Managing protein activity in A. thaliana},
school = {Universit{\"a}t Potsdam},
pages = {160},
year = {2017},
language = {en}
}
@article{TiedemannIobbiNivolLeimkuehler2022,
author = {Tiedemann, Kim and Iobbi-Nivol, Chantal and Leimk{\"u}hler, Silke},
title = {The Role of the Nucleotides in the Insertion of the bis-Molybdopterin Guanine Dinucleotide Cofactor into apo-Molybdoenzymes},
series = {Molecules},
volume = {27},
journal = {Molecules},
edition = {9},
publisher = {MDPI},
address = {Basel, Schweiz},
issn = {1420-3049},
doi = {10.3390/molecules27092993},
pages = {1 -- 15},
year = {2022},
abstract = {The role of the GMP nucleotides of the bis-molybdopterin guanine dinucleotide (bis-MGD) cofactor of the DMSO reductase family has long been a subject of discussion. The recent characterization of the bis-molybdopterin (bis-Mo-MPT) cofactor present in the E. coli YdhV protein, which differs from bis-MGD solely by the absence of the nucleotides, now enables studying the role of the nucleotides of bis-MGD and bis-MPT cofactors in Moco insertion and the activity of molybdoenzymes in direct comparison. Using the well-known E. coli TMAO reductase TorA as a model enzyme for cofactor insertion, we were able to show that the GMP nucleotides of bis-MGD are crucial for the insertion of the bis-MGD cofactor into apo-TorA.},
language = {en}
}
@phdthesis{Unterstab2005,
author = {Unterstab, Gunhild},
title = {Charakterisierung der viralen Genprodukte p10 und P des Borna Disease Virus},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-6905},
school = {Universit{\"a}t Potsdam},
year = {2005},
abstract = {Das Borna Disease Virus (BDV, Bornavirus) besitzt ein einzelstr{\"a}ngiges RNA-Genom negativer Polarit{\"a}t und ist innerhalb der Ordnung Mononegavirales der Prototyp einer eigenen Virusfamilie, die der Bornaviridae. Eine außergew{\"o}hnliche Eigenschaft des Virus ist seine nukle{\"a}re Transkription und Replikation, eine weitere besteht in seiner F{\"a}higkeit, als neurotropes Virus sowohl in vivo als auch in vitro persistente Infektionen zu etablieren. Die zugrunde liegenden Mechanismen sowohl der Replikation als auch der Persistenz sind derzeit noch unzureichend verstanden, auch deshalb, weil das Virus noch relativ „jung" ist: Erste komplette Sequenzen des RNA-Genoms wurden 1994 publiziert und erst vor einigen Monaten gelang die Generierung rekombinanter Viren auf der Basis klonierter cDNA. Im Mittelpunkt dieser Arbeit standen das p10 Protein und das Phosphoprotein (P), die von der gemeinsamen Transkriptionseinheit II in {\"u}berlappenden Leserahmen kodiert werden. Als im Kern der Wirtszelle replizierendes Virus ist das Bornavirus auf zellul{\"a}re Importmechanismen angewiesen, um den Kernimport aller an der Replikation beteiligten viralen Proteine zu gew{\"a}hrleisten. Das p10 Protein ist ein negativer Regulator der viralen RNA-abh{\"a}ngigen RNA-Polymerase (L). In vitro Importexperimente zeigten, dass p10 {\"u}ber den klassischen Importin alpha/beta abh{\"a}ngigen Kernimportweg in den Nukleus transportiert wird. Dies war unerwartet, da p10 kein vorhersagbares klassisches Kernlokalisierungssignal (NLS) besitzt und weist darauf hin, dass der zellul{\"a}re Importapparat offensichtlich flexibler ist als allgemein angenommen. Die ersten 20 N-terminalen AS vermitteln sowohl Kernimport als auch die Bindung an den Importrezeptor Importin alpha. Durch Di-Alanin-Austauschmutagenese wurden die f{\"u}r diesen Transportprozess essentiellen AS identifiziert und die Bedeutung hydrophober und polarer AS-Reste demonstriert. Die F{\"a}higkeit des Bornavirus, persistente Infektionen zu etablieren, wirft die Frage auf, wie das Virus die zellul{\"a}ren antiviralen Abwehrmechanismen, insbesondere das Typ I Interferon (IFN)-System, unterwandert. Das virale P Protein wurde in dieser Arbeit als potenter Antagonist der IFN-Induktion charakterisiert. Es verhindert die Phosphorylierung des zentralen Transkriptionsfaktors IRF3 durch die zellul{\"a}re Kinase TBK1 und somit dessen Aktivierung. Der Befund, dass P mit TBK1 Komplexe bildet und zudem auch als Substrat f{\"u}r die zellul{\"a}re Kinase fungiert, erlaubt es, erstmalig einen Mechanismus zu postulieren, in dem ein virales Protein (BDV-P) als putatives TBK1-Pseudosubstrat die IRF3-Aktivierung kompetitiv hemmt.},
subject = {Interferon },
language = {de}
}
@misc{WackervonElert2001,
author = {Wacker, Alexander and von Elert, Eric},
title = {Polyunsaturated fatty acids : evidence for non-substitutable biochemical resources in Daphnia galeata},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17587},
year = {2001},
abstract = {The factors that determine the efficiency of energy transfer in aquatic food webs have been investigated for many decades. The plant-animal interface is the most variable and least predictable of all levels in the food web. In order to study determinants of food quality in a large lake and to test the recently proposed central importance of the long-chained eicosapentaenoic acid (EPA) at the pelagic producer-grazer interface, we tested the importance of polyunsaturated fatty acids (PUFAs) at the pelagic producerconsumer interface by correlating sestonic food parameters with somatic growth rates of a clone of Daphnia galeata. Daphnia growth rates were obtained from standardized laboratory experiments spanning one season with Daphnia feeding on natural seston from Lake Constance, a large pre-alpine lake. Somatic growth rates were fitted to sestonic parameters by using a saturation function. A moderate amount of variation was explained when the model included the elemental parameters carbon (r2 = 0.6) and nitrogen (r2 = 0.71). A tighter fit was obtained when sestonic phosphorus was incorporated (r2 = 0.86). The nonlinear regression with EPA was relatively weak (r2 = 0.77), whereas the highest degree of variance was explained by three C18-PUFAs. The best (r2 = 0.95), and only significant, correlation of Daphnia's growth was found with the C18-PUFA α-linolenic acid (α-LA; C18:3n-3). This correlation was weakest in late August when C:P values increased to 300, suggesting that mineral and PUFA-limitation of Daphnia's growth changed seasonally. Sestonic phosphorus and some PUFAs showed not only tight correlations with growth, but also with sestonic α-LA content. We computed Monte Carlo simulations to test whether the observed effects of α-LA on growth could be accounted for by EPA, phosphorus, or one of the two C18-PUFAs, stearidonic acid (C18:4n-3) and linoleic acid (C18:2n-6). With >99 \% probability, the correlation of growth with α-LA could not be explained by any of these parameters. In order to test for EPA limitation of Daphnia's growth, in parallel with experiments on pure seston, growth was determined on seston supplemented with chemostat-grown, P-limited Stephanodiscus hantzschii, which is rich in EPA. Although supplementation increased the EPA content 80-800x, no significant changes in the nonlinear regression of the growth rates with α-LA were found, indicating that growth of Daphnia on pure seston was not EPA limited. This indicates that the two fatty acids, EPA and α-LA, were not mutually substitutable biochemical resources and points to different physiological functions of these two PUFAs. These results support the PUFA-limitation hypothesis for sestonic C:P < 300 but are contrary to the hypothesis of a general importance of EPA, since no evidence for EPA limitation was found. It is suggested that the resource ratios of EPA and α-LA rather than the absolute concentrations determine which of the two resources is limiting growth.},
language = {en}
}
@misc{WackervonElert2002,
author = {Wacker, Alexander and von Elert, Eric},
title = {Strong influences of larval diet history on subsequent post-settlement growth in the freshwater mollusc Dreissena polymorpha},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17627},
year = {2002},
abstract = {Significant seasonal variation in size at settlement has been observed in newly settled larvae of Dreissena polymorpha in Lake Constance. Diet quality, which varies temporally and spatially in freshwater habitats, has been suggested as a significant factor influencing life history and development of freshwater invertebrates. Accordingly, experiments were conducted with field-collected larvae to test the hypothesis that diet quality can determine planktonic larval growth rates, size at settlement and subsequent post-metamorphic growth rates. Larvae were fed one of two diets or starved. One diet was composed of cyanobacterial cells which are deficient in polyunsaturated fatty acids (PUFAs), and the other was a mixed diet rich in PUFAs. Freshly metamorphosed animals from the starvation treatment had a carbon content per individual 70\% lower than that of larvae fed the mixed diet. This apparent exhaustion of larval internal reserves resulted in a 50\% reduction of the postmetamorphic growth rates. Growth was also reduced in animals previously fed the cyanobacterial diet. Hence, low food quantity or low food quality during the larval stage of D. polymorpha lead to irreversible effects for postmetamorphic animals, and is related to inferior competitive abilities.},
language = {en}
}
@phdthesis{Wagner2007,
author = {Wagner, Dirk},
title = {Microbial perspectives of the methane cycle in permafrost ecosystems in the Eastern Siberian Arctic : implications for the global methane budget},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15434},
school = {Universit{\"a}t Potsdam},
year = {2007},
abstract = {The Arctic plays a key role in Earth's climate system as global warming is predicted to be most pronounced at high latitudes and because one third of the global carbon pool is stored in ecosystems of the northern latitudes. In order to improve our understanding of the present and future carbon dynamics in climate sensitive permafrost ecosystems, the present study concentrates on investigations of microbial controls of methane fluxes, on the activity and structure of the involved microbial communities, and on their response to changing environmental conditions. For this purpose an integrated research strategy was applied, which connects trace gas flux measurements to soil ecological characterisation of permafrost habitats and molecular ecological analyses of microbial populations. Furthermore, methanogenic archaea isolated from Siberian permafrost have been used as potential keystone organisms for studying and assessing life under extreme living conditions. Long-term studies on methane fluxes were carried out since 1998. These studies revealed considerable seasonal and spatial variations of methane emissions for the different landscape units ranging from 0 to 362 mg m-2 d-1. For the overall balance of methane emissions from the entire delta, the first land cover classification based on Landsat images was performed and applied for an upscaling of the methane flux data sets. The regionally weighted mean daily methane emissions of the Lena Delta (10 mg m-2 d-1) are only one fifth of the values calculated for other Arctic tundra environments. The calculated annual methane emission of the Lena Delta amounts to about 0.03 Tg. The low methane emission rates obtained in this study are the result of the used remotely sensed high-resolution data basis, which provides a more realistic estimation of the real methane emissions on a regional scale. Soil temperature and near soil surface atmospheric turbulence were identified as the driving parameters of methane emissions. A flux model based on these variables explained variations of the methane budget corresponding to continuous processes of microbial methane production and oxidation, and gas diffusion through soil and plants reasonably well. The results show that the Lena Delta contributes significantly to the global methane balance because of its extensive wetland areas. The microbiological investigations showed that permafrost soils are colonized by high numbers of microorganisms. The total biomass is comparable to temperate soil ecosystems. Activities of methanogens and methanotrophs differed significantly in their rates and distribution patterns along both the vertical profiles and the different investigated soils. The methane production rates varied between 0.3 and 38.9 nmol h-1 g-1, while the methane oxidation ranged from 0.2 to 7.0 nmol h-1 g-1. Phylogenetic analyses of methanogenic communities revealed a distinct diversity of methanogens affiliated to Methanomicrobiaceae, Methanosarcinaceae and Methanosaetaceae, which partly form four specific permafrost clusters. The results demonstrate the close relationship between methane fluxes and the fundamental microbiological processes in permafrost soils. The microorganisms do not only survive in their extreme habitat but also can be metabolic active under in situ conditions. It was shown that a slight increase of the temperature can lead to a substantial increase in methanogenic activity within perennially frozen deposits. In case of degradation, this would lead to an extensive expansion of the methane deposits with their subsequent impacts on total methane budget. Further studies on the stress response of methanogenic archaea, especially Methanosarcina SMA-21, isolated from Siberian permafrost, revealed an unexpected resistance of the microorganisms against unfavourable living conditions. A better adaptation to environmental stress was observed at 4 °C compared to 28 °C. For the first time it could be demonstrated that methanogenic archaea from terrestrial permafrost even survived simulated Martian conditions. The results show that permafrost methanogens are more resistant than methanogens from non-permafrost environments under Mars-like climate conditions. Microorganisms comparable to methanogens from terrestrial permafrost can be seen as one of the most likely candidates for life on Mars due to their physiological potential and metabolic specificity.},
language = {en}
}
@article{WeithoffBell2022,
author = {Weithoff, Guntram and Bell, Elanor Margaret},
title = {Complex Trophic Interactions in an Acidophilic Microbial Community},
series = {Microorganisms},
volume = {10},
journal = {Microorganisms},
edition = {7},
publisher = {MDPI},
address = {Basel, Schweiz},
issn = {2076-2607},
doi = {10.3390/microorganisms10071340},
pages = {1 -- 10},
year = {2022},
abstract = {Extreme habitats often harbor specific communities that differ substantially from non-extreme habitats. In many cases, these communities are characterized by archaea, bacteria and protists, whereas the number of species of metazoa and higher plants is relatively low. In extremely acidic habitats, mostly prokaryotes and protists thrive, and only very few metazoa thrive, for example, rotifers. Since many studies have investigated the physiology and ecology of individual species, there is still a gap in research on direct, trophic interactions among extremophiles. To fill this gap, we experimentally studied the trophic interactions between a predatory protist (Actinophrys sol, Heliozoa) and its prey, the rotifers Elosa woralli and Cephalodella sp., the ciliate Urosomoida sp. and the mixotrophic protist Chlamydomonas acidophila (a green phytoflagellate, Chlorophyta). We found substantial predation pressure on all animal prey. High densities of Chlamydomonas acidophila reduced the predation impact on the rotifers by interfering with the feeding behaviour of A. sol. These trophic relations represent a natural case of intraguild predation, with Chlamydomonas acidophila being the common prey and the rotifers/ciliate and A. sol being the intraguild prey and predator, respectively. We further studied this intraguild predation along a resource gradient using Cephalodella sp. as the intraguild prey. The interactions among the three species led to an increase in relative rotifer abundance with increasing resource (Chlamydomonas) densities. By applying a series of laboratory experiments, we revealed the complexity of trophic interactions within a natural extremophilic community.},
language = {en}
}
@phdthesis{Wenk2020,
author = {Wenk, Sebastian},
title = {Engineering formatotrophic growth in Escherichia coli},
school = {Universit{\"a}t Potsdam},
pages = {V, 107},
year = {2020},
abstract = {To meet the demands of a growing world population while reducing carbon dioxide (CO2) emissions, it is necessary to capture CO2 and convert it into value-added compounds. In recent years, metabolic engineering of microbes has gained strong momentum as a strategy for the production of valuable chemicals. As common microbial feedstocks like glucose directly compete with human consumption, the one carbon (C1) compound formate was suggested as an alternative feedstock. Formate can be easily produced by various means including electrochemical reduction of CO2 and could serve as a feedstock for microbial production, hence presenting a novel entry point for CO2 to the biosphere and a storage option for excess electricity. Compared to the gaseous molecule CO2, formate is a highly soluble compound that can be easily handled and stored. It can serve as a carbon and energy source for natural formatotrophs, but these microbes are difficult to cultivate and engineer. In this work, I present the results of several projects that aim to establish efficient formatotrophic growth of E. coli - which cannot naturally grow on formate - via synthetic formate assimilation pathways. In the first study, I establish a workflow for growth-coupled metabolic engineering of E. coli. I demonstrate this approach by presenting an engineering scheme for the PFL-threonine cycle, a synthetic pathway for anaerobic formate assimilation in E. coli. The described methods are intended to create a standardized toolbox for engineers that aim to establish novel metabolic routes in E. coli and related organisms. The second chapter presents a study on the catalytic efficiency of C1-oxidizing enzymes in vivo. As formatotrophic growth requires generation of both energy and biomass from formate, the engineered E. coli strains need to be equipped with a highly efficient formate dehydrogenase, which provides reduction equivalents and ATP for formate assimilation. I engineered a strain that cannot generate reducing power and energy for cellular growth, when fed on acetate. Under this condition, the strain depends on the introduction of an enzymatic system for NADH regeneration, which could further produce ATP via oxidative phosphorylation. I show that the strain presents a valuable testing platform for C1-oxidizing enzymes by testing different NAD-dependent formate and methanol dehydrogenases in the energy auxotroph strain. Using this platform, several candidate enzymes with high in vivo activity, were identified and characterized as potential energy-generating systems for synthetic formatotrophic or methylotrophic growth in E. coli. In the third chapter, I present the establishment of the serine threonine cycle (STC) - a synthetic formate assimilation pathway - in E. coli. In this pathway, formate is assimilated via formate tetrahydrofolate ligase (FtfL) from Methylobacterium extorquens (M. extorquens). The carbon from formate is attached to glycine to produce serine, which is converted into pyruvate entering central metabolism. Via the natural threonine synthesis and cleavage route, glycine is regenerated and acetyl-CoA is produced as the pathway product. I engineered several selection strains that depend on different STC modules for growth and determined key enzymes that enable high flux through threonine synthesis and cleavage. I could show that expression of an auxiliary formate dehydrogenase was required to achieve growth via threonine synthesis and cleavage on pyruvate. By overexpressing most of the pathway enzymes from the genome, and applying adaptive laboratory evolution, growth on glycine and formate was achieved, indicating the activity of the complete cycle. The fourth chapter shows the establishment of the reductive glycine pathway (rGP) - a short, linear formate assimilation route - in E. coli. As in the STC, formate is assimilated via M. extorquens FtfL. The C1 from formate is condensed with CO2 via the reverse reaction of the glycine cleavage system to produce glycine. Another carbon from formate is attached to glycine to form serine, which is assimilated into central metabolism via pyruvate. The engineered E. coli strain, expressing most of the pathway genes from the genome, can grow via the rGP with formate or methanol as a sole carbon and energy source.},
language = {en}
}
@phdthesis{Yishai2019,
author = {Yishai, Oren},
title = {Engineering the reductive glycine pathway in Escherichia coli},
school = {Universit{\"a}t Potsdam},
pages = {86},
year = {2019},
language = {en}
}
@phdthesis{Ziege2022,
author = {Ziege, Ricardo},
title = {Growth dynamics and mechanical properties of E. coli biofilms},
doi = {10.25932/publishup-55986},
url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-559869},
school = {Universit{\"a}t Potsdam},
pages = {xi, 123},
year = {2022},
abstract = {Biofilms are complex living materials that form as bacteria get embedded in a matrix of self-produced protein and polysaccharide fibres. The formation of a network of extracellular biopolymer fibres contributes to the cohesion of the biofilm by promoting cell-cell attachment and by mediating biofilm-substrate interactions. This sessile mode of bacteria growth has been well studied by microbiologists to prevent the detrimental effects of biofilms in medical and industrial settings. Indeed, biofilms are associated with increased antibiotic resistance in bacterial infections, and they can also cause clogging of pipelines or promote bio-corrosion. However, biofilms also gained interest from biophysics due to their ability to form complex morphological patterns during growth. Recently, the emerging field of engineered living materials investigates biofilm mechanical properties at multiple length scales and leverages the tools of synthetic biology to tune the functions of their constitutive biopolymers. This doctoral thesis aims at clarifying how the morphogenesis of Escherichia coli (E. coli) biofilms is influenced by their growth dynamics and mechanical properties. To address this question, I used methods from cell mechanics and materials science. I first studied how biological activity in biofilms gives rise to non-uniform growth patterns. In a second study, I investigated how E. coli biofilm morphogenesis and its mechanical properties adapt to an environmental stimulus, namely the water content of their substrate. Finally, I estimated how the mechanical properties of E. coli biofilms are altered when the bacteria express different extracellular biopolymers. On nutritive hydrogels, micron-sized E. coli cells can build centimetre-large biofilms. During this process, bacterial proliferation and matrix production introduce mechanical stresses in the biofilm, which release through the formation of macroscopic wrinkles and delaminated buckles. To relate these biological and mechanical phenomena, I used time-lapse fluorescence imaging to track cell and matrix surface densities through the early and late stages of E. coli biofilm growth. Colocalization of high cell and matrix densities at the periphery precede the onset of mechanical instabilities at this annular region. Early growth is detected at this outer annulus, which was analysed by adding fluorescent microspheres to the bacterial inoculum. But only when high rates of matrix production are present in the biofilm centre, does overall biofilm spreading initiate along the solid-air interface. By tracking larger fluorescent particles for a long time, I could distinguish several kinematic stages of E. coli biofilm expansion and observed a transition from non-linear to linear velocity profiles, which precedes the emergence of wrinkles at the biofilm periphery. Decomposing particle velocities to their radial and circumferential components revealed a last kinematic stage, where biofilm movement is mostly directed towards the radial delaminated buckles, which verticalize. The resulting compressive strains computed in these regions were observed to substantially deform the underlying agar substrates. The co-localization of higher cell and matrix densities towards an annular region and the succession of several kinematic stages are thus expected to promote the emergence of mechanical instabilities at the biofilm periphery. These experimental findings are predicted to advance future modelling approaches of biofilm morphogenesis. E. coli biofilm morphogenesis is further anticipated to depend on external stimuli from the environment. To clarify how the water could be used to tune biofilm material properties, we quantified E. coli biofilm growth, wrinkling dynamics and rigidity as a function of the water content of the nutritive substrates. Time-lapse microscopy and computational image analysis revealed that substrates with high water content promote biofilm spreading kinetics, while substrates with low water content promote biofilm wrinkling. The wrinkles observed on biofilm cross-sections appeared more bent on substrates with high water content, while they tended to be more vertical on substrates with low water content. Both wet and dry biomass, accumulated over 4 days of culture, were larger in biofilms cultured on substrates with high water content, despite extra porosity within the matrix layer. Finally, the micro-indentation analysis revealed that substrates with low water content supported the formation of stiffer biofilms. This study shows that E. coli biofilms respond to the water content of their substrate, which might be used for tuning their material properties in view of further applications. Biofilm material properties further depend on the composition and structure of the matrix of extracellular proteins and polysaccharides. In particular, E. coli biofilms were suggested to present tissue-like elasticity due to a dense fibre network consisting of amyloid curli and phosphoethanolamine-modified cellulose. To understand the contribution of these components to the emergent mechanical properties of E. coli biofilms, we performed micro-indentation on biofilms grown from bacteria of several strains. Besides showing higher dry masses, larger spreading diameters and slightly reduced water contents, biofilms expressing both main matrix components also presented high rigidities in the range of several hundred kPa, similar to biofilms containing only curli fibres. In contrast, a lack of amyloid curli fibres provides much higher adhesive energies and more viscoelastic fluid-like material behaviour. Therefore, the combination of amyloid curli and phosphoethanolamine-modified cellulose fibres implies the formation of a composite material whereby the amyloid curli fibres provide rigidity to E. coli biofilms, whereas the phosphoethanolamine-modified cellulose rather acts as a glue. These findings motivate further studies involving purified versions of these protein and polysaccharide components to better understand how their interactions benefit biofilm functions. All three studies depict different aspects of biofilm morphogenesis, which are interrelated. The first work reveals the correlation between non-uniform biological activities and the emergence of mechanical instabilities in the biofilm. The second work acknowledges the adaptive nature of E. coli biofilm morphogenesis and its mechanical properties to an environmental stimulus, namely water. Finally, the last study reveals the complementary role of the individual matrix components in the formation of a stable biofilm material, which not only forms complex morphologies but also functions as a protective shield for the bacteria it contains. Our experimental findings on E. coli biofilm morphogenesis and their mechanical properties can have further implications for fundamental and applied biofilm research fields.},
language = {en}
}
@article{ZurellKoenigMalchowetal.2022,
author = {Zurell, Damaris and K{\"o}nig, Christian and Malchow, Anne-Kathleen and Kapitza, Simon and Bocedi, Greta and Travis, Justin M. J. and Fandos, Guillermo},
title = {Spatially explicit models for decision-making in animal conservation and restoration},
series = {Ecography : pattern and diversity in ecology / Nordic Ecologic Society Oikos},
journal = {Ecography : pattern and diversity in ecology / Nordic Ecologic Society Oikos},
number = {4},
publisher = {Wiley-Blackwell},
address = {Oxford},
issn = {1600-0587},
doi = {10.1111/ecog.05787},
pages = {1 -- 16},
year = {2022},
abstract = {Models are useful tools for understanding and predicting ecological patterns and processes. Under ongoing climate and biodiversity change, they can greatly facilitate decision-making in conservation and restoration and help designing adequate management strategies for an uncertain future. Here, we review the use of spatially explicit models for decision support and to identify key gaps in current modelling in conservation and restoration. Of 650 reviewed publications, 217 publications had a clear management application and were included in our quantitative analyses. Overall, modelling studies were biased towards static models (79\%), towards the species and population level (80\%) and towards conservation (rather than restoration) applications (71\%). Correlative niche models were the most widely used model type. Dynamic models as well as the gene-to-individual level and the community-to-ecosystem level were underrepresented, and explicit cost optimisation approaches were only used in 10\% of the studies. We present a new model typology for selecting models for animal conservation and restoration, characterising model types according to organisational levels, biological processes of interest and desired management applications. This typology will help to more closely link models to management goals. Additionally, future efforts need to overcome important challenges related to data integration, model integration and decision-making. We conclude with five key recommendations, suggesting that wider usage of spatially explicit models for decision support can be achieved by 1) developing a toolbox with multiple, easier-to-use methods, 2) improving calibration and validation of dynamic modelling approaches and 3) developing best-practise guidelines for applying these models. Further, more robust decision-making can be achieved by 4) combining multiple modelling approaches to assess uncertainty, and 5) placing models at the core of adaptive management. These efforts must be accompanied by long-term funding for modelling and monitoring, and improved communication between research and practise to ensure optimal conservation and restoration outcomes.},
language = {en}
}