21 results on '"Tobias Gold"'
Search Results
2. Catching Objects with a Robot Arm using Model Predictive Control.
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Tobias Gold, Ralf Römer, Andreas Völz, and Knut Graichen
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- 2022
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3. Model Predictive Interaction Control for Force Closure Grasping.
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Tobias Gold, Martin Rohrmüller, Andreas Völz, and Knut Graichen
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- 2021
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4. Model Predictive Position and Force Trajectory Tracking Control for Robot-Environment Interaction.
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Tobias Gold, Andreas Völz, and Knut Graichen
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- 2020
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5. Model Predictive Interaction Control based on a Path-Following Formulation
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Tim Goller, Tobias Gold, Andreas Volz, and Knut Graichen
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- 2022
6. Unpredicted ecosystem response to compound human impacts in a European river
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Jan Köhler, Elisabeth Varga, Stephanie Spahr, Jörn Gessner, Kerstin Stelzer, Gunnar Brandt, Miguel D. Mahecha, Guido Kraemer, Martin Pusch, Christian Wolter, Michael T. Monaghan, Matthias Stöck, and Tobias Goldhammer
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Harmful algal bloom ,Prymnesium parvum ,Fish kill ,Salinization ,River ecology ,Multiple stressors ,Medicine ,Science - Abstract
Abstract Climate change elevates the threat of compound heat and drought events, with their ecological and socioeconomic impacts exacerbated by human ecosystem alterations such as eutrophication, salinization, and river engineering. Here, we study how multiple stressors produced an environmental disaster in a large European river, the Oder River, where a toxic bloom of the brackish-water planktonic haptophyte Prymnesium parvum (the “golden algae”) killed approximately 1000 metric tons of fish and most mussels and snails. We uncovered the complexity of this event using hydroclimatic data, remote sensing, cell counts, hydrochemical and toxin analyses, and genetics. After incubation in impounded upstream channels with drastically elevated concentrations of salts and nutrients, only a critical combination of chronic salt and nutrient pollution, acute high water temperatures, and low river discharge during a heatwave enabled the riverine mass proliferation of B-type P. parvum along a 500 km river section. The dramatic losses of large filter feeders and the spreading of vegetative cells and resting stages make the system more susceptible to new harmful algal blooms. Our findings show that global warming, water use intensification, and chronic ecosystem pollution could increase likelihood and severity of such compound ecoclimatic events, necessitating consideration in future impact models.
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- 2024
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7. PERPRISE: A prospective non‐interventional study of PERampanel as only adjunctive treatment in patients with PRImary or SEcondarily generalized tonic–clonic seizures: First interim analysis
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Bernhard J Steinhoff, Tobias Goldmann, Edgar Kockelmann, Yaroslav Winter, and for the PERPRISE Study Group
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epilepsy ,Germany ,perampanel ,real world ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Objective To report the interim results of the PERPRISE study (Study 509; NCT04202159), which is evaluating perampanel as the only adjunctive anti‐seizure medication (ASM) in adults with focal to bilateral tonic–clonic seizures (FBTCS) or primary generalized tonic–clonic seizures (GTCS). Methods PERPRISE is an ongoing 12‐month multicenter, prospective, observational, non‐interventional study of perampanel in a real‐world setting in Germany. Patients are aged ≥18 years with FBTCS or GTCS due to focal or idiopathic generalized epilepsy. Perampanel, as an adjunctive therapy to ASM monotherapy (‘add‐on therapy’) or as a substitute for one ASM in dual therapy (‘substitution therapy’), is prescribed in line with its SmPC. The Interim Analysis Set comprises the first 100 patients who received ≥1 dose of perampanel and attended or discontinued prior to the ~6‐month visit. Interim endpoints include retention rate, measures of effects on seizure frequency, and treatment‐emergent adverse events (TEAEs). Results One hundred patients were included in the Interim Analysis Set (add‐on, n = 43 [43.0%]; substitution, n = 55 [55.0%]; unknown, n = 2). The 6‐month retention rate was 78.0% (add‐on, 83.7%; substitution, 72.7%). For the overall population with GTCS and/or FBTCS, seizure‐freedom rate at 6 months was 58.8% (add‐on, 72.2%; substitution, 47.9%) and 50% responder rate at 6 months was 82.6% (add‐on, 89.2%; substitution, 76.6%). Retention rates and seizure outcomes were better with perampanel as an early‐line treatment than as a late‐line treatment. TEAEs were reported by 48 patients (48.0%), most commonly dizziness (n = 9), fatigue (n = 7), and irritability (n = 7). Sixteen patients (16.0%) withdrew from perampanel treatment due to TEAEs. Significance The interim analysis of PERPRISE offers insight into the real‐world use of perampanel in Germany, including for the first time, clinical practice data from patients with GTCS and switching ASMs within a dual therapy. Further data from PERPRISE will be of value to inform clinical decision‐making in this patient cohort. Plain Language Summary Patients with epilepsy often take more than one medication for seizure control. This 12month study looked at patients in Germany receiving perampanel as only add‐on medication. The interim analysis shows, that at 6 months, over 70% of the 100 patients continued to use perampanel; 59% experienced no seizures during treatment with perampanel, and in 83%, seizure frequency was reduced by half. Side effects occurred in 48% of patients (most commonly dizziness, fatigue, and irritability) and caused 16% to withdraw from the study. Overall, perampanel was a suitable as only add‐on medication for patients with epilepsy.
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- 2024
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8. Model Predictive Interaction Control for Industrial Robots
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Tobias Gold, Knut Graichen, and Andreas Volz
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0209 industrial biotechnology ,State variable ,Computer science ,020208 electrical & electronic engineering ,Dynamics (mechanics) ,02 engineering and technology ,Rigid body dynamics ,Motion control ,law.invention ,Computer Science::Robotics ,Industrial robot ,Model predictive control ,020901 industrial engineering & automation ,Control and Systems Engineering ,Control theory ,law ,0202 electrical engineering, electronic engineering, information engineering ,Torque ,Robot - Abstract
This paper discusses the use of model predictive control (MPC) for industrial robot applications with physical robot-environmental interaction. A model predictive interaction control (MPIC) scheme is introduced that deals both with the prediction of the robot motion and the forces between robot and environment. With regard to the robot motion, either the rigid body dynamics, a simplified model, or a cascaded control structure can be employed. The external forces or torques are treated as additional state variables whose dynamics are based on the elastic behavior of the contact surface. Since the force prediction depends on the knowledge of the environmental stiffness, a method for online estimation is discussed. The approach allows to realize different tasks as motion control, compliance control, direct force control as well as hybrid force/motion control by adjusting the weighting factors in the cost function. The implementation is based on the nonlinear MPC software Grampc and the library Pinocchio for computation of rigid body dynamics. Besides comparing the different robot dynamics models, the approach is demonstrated for a hand-guiding and a table wiping task.
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- 2020
9. External Torque Estimation for an Industrial Robot Arm using Joint Torsion and Motor Current Measurements
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Tobias Gold, Andreas Volz, and Knut Graichen
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0209 industrial biotechnology ,Computer science ,020208 electrical & electronic engineering ,Torsion (mechanics) ,02 engineering and technology ,Human–robot interaction ,law.invention ,Computer Science::Robotics ,Industrial robot ,020901 industrial engineering & automation ,Control and Systems Engineering ,law ,Control theory ,0202 electrical engineering, electronic engineering, information engineering ,Robot ,Torque - Abstract
Human robot collaboration requires specific properties of modern lightweight robots that differ from conventional robots. One of these is the property of reacting to external forces acting on the robot structure, which typically requires joint torque measurements. In contrast to that, this paper presents an approach for estimating the external joint torques based on two different information sources, the motor current and the torsional deformation. To obtain an accurate estimation based on the torsional deformation, disturbing effects and inaccuracies of the angular measurements have to be taken into account. An approach for modeling, identification and cancellation of these effects is presented. Furthermore, the fusion of both estimations is discussed and the validation of the approach on a lightweight robot is presented.
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- 2019
10. Universal microbial reworking of dissolved organic matter along environmental gradients
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Erika C. Freeman, Erik J. S. Emilson, Thorsten Dittmar, Lucas P. P. Braga, Caroline E. Emilson, Tobias Goldhammer, Christine Martineau, Gabriel Singer, and Andrew J. Tanentzap
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Science - Abstract
Abstract Soils are losing increasing amounts of carbon annually to freshwaters as dissolved organic matter (DOM), which, if degraded, can offset their carbon sink capacity. However, the processes underlying DOM degradation across environments are poorly understood. Here we show DOM changes similarly along soil-aquatic gradients irrespective of environmental differences. Using ultrahigh-resolution mass spectrometry, we track DOM along soil depths and hillslope positions in forest catchments and relate its composition to soil microbiomes and physico-chemical conditions. Along depths and hillslopes, we find carbohydrate-like and unsaturated hydrocarbon-like compounds increase in abundance-weighted mass, and the expression of genes essential for degrading plant-derived carbohydrates explains >50% of the variation in abundance of these compounds. These results suggest that microbes transform plant-derived compounds, leaving DOM to become increasingly dominated by the same (i.e., universal), difficult-to-degrade compounds as degradation proceeds. By synthesising data from the land-to-ocean continuum, we suggest these processes generalise across ecosystems and spatiotemporal scales. Such general degradation patterns can help predict DOM composition and reactivity along environmental gradients to inform management of soil-to-stream carbon losses.
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- 2024
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11. Towards a Generic Manipulation Framework for Robots based on Model Predictive Interaction Control
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Alexander Lomakin, Knut Graichen, Tim Goller, Andreas Volz, and Tobias Gold
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Computer science ,business.industry ,media_common.quotation_subject ,Degrees of freedom (mechanics) ,Task (project management) ,Computer Science::Robotics ,Control theory ,Key (cryptography) ,Decomposition (computer science) ,Robot ,Artificial intelligence ,business ,Function (engineering) ,Robotic arm ,media_common - Abstract
This paper presents an optimization-based control framework for robotic manipulation tasks. A hierarchical and systematic decomposition is used in order to formulate the high-level task as a sequence of manipulation primitives. A key difficulty is that different primitives usually require different strategies to control motions and forces. However, based on the concept of model predictive interaction control (MPIC), it is possible to use the same control approach for all primitives. Instead of changing the controller, only the parameterization of the MPIC, i.e. the cost function and the constraints, is adapted for each primitive. The hierarchical task decomposition and the generic control concept are demonstrated for a screwing application using a robot arm with seven degrees of freedom.
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- 2020
12. Response of cyanobacterial mats to ambient phosphate fluctuations: phosphorus cycling, polyphosphate accumulation and stoichiometric flexibility
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Laura Jentzsch, Hans-Peter Grossart, Sascha Plewe, Dirk Schulze-Makuch, and Tobias Goldhammer
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Microbial ecology ,QR100-130 - Abstract
Abstract Cyanobacterial mats inhabit a variety of aquatic habitats, including the most extreme environments on Earth. They can thrive in a wide range of phosphorus (P) levels and are thus important players for ecosystem primary production and P cycling at the sediment-water interface. Polyphosphate (polyP), the major microbial P storage molecule, is assigned a critical role in compensating for phosphate fluctuations in planktonic cyanobacteria, but little is known about potentially analogous mechanisms of mat-forming cyanobacteria. To investigate acclimation strategies of cyanobacterial mats to fluctuating phosphate concentrations, laboratory batch experiments were conducted, in which the cosmopolitan mat-forming, marine cyanobacterium Sodalinema stali was exposed to low dissolved P concentrations, followed by a P pulse. Our results show that the cyanobacteria dynamically adjusted cellular P content to ambient phosphate concentrations and that they had accumulated polyP during periods of high phosphate availability, which was subsequently recycled to sustain growth during phosphate scarcity. However, following the depletion of dispensable cellular P sources, including polyP, we observed a reallocation of P contained in DNA into polyP, accompanied by increasing alkaline phosphatase activity. This suggests a change of the metabolic focus from growth towards maintenance and the attempt to acquire organic P, which would be naturally contained in the sediment. P overplus uptake following a simulated P pulse further suggests that Sodalinema-dominated mats exhibit elaborated mechanisms to cope with severe P fluctuations to overcome unfavourable environmental conditions, and potentially modulate critical P fluxes in the aquatic cycle.
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- 2023
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13. An approach to difficult airway in infants: Comparison of GlideScope® Spectrum LoPro, GlideScope® Spectrum Miller and conventional Macintosh and Miller blades in a simulated Pierre Robin sequence performed by 90 anesthesiologists.
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Andrea Irouschek, Andreas Moritz, Sven Kremer, Tobias Fuchte, Anja Danzl, Joachim Schmidt, and Tobias Golditz
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Medicine ,Science - Abstract
BackgroundAirway management can be challenging in neonates and infants. The Pierre Robin sequence (PRS) is a condition characterized by micrognathia, glossoptosis and airway obstruction. The airway management of these patients poses great challenges for anesthesiologists and pediatricians alike. To date, there has been no direct comparison of the hyperangulated GlideScope® Spectrum LoPro (GLP), the straight GlideScope® Spectrum Miller (GSM), a conventional Macintosh (MC) and a conventional Miller blade (ML) in patients with PRS.MethodsFor this purpose, 90 anesthesiologists (43 with limited experience, 47 with extensive experience) performed orotracheal intubation on an Air-Sim® Pierre Robin X manikin using GLP, GSM, MC and ML in randomized order. 'Time-to-vocal-cords', 'time-to-intubate', 'time-to-ventilate', the severity of oral-soft-tissue-trauma and the subjective evaluation of each device were recorded.ResultsA significantly faster and better view of the vocal cords and lower oral-soft-tissue-trauma was achieved using the GLP (p120s) with the GLP. In the sub-group with extensive experience, we found significantly shorter intubation times for the GSM and ML. The GLP was the tool of choice for most participants, while the conventional MC received the lowest rating.ConclusionsVideolaryngoscopy leads to increased safety for the prevention of undetected esophageal intubation in the airway management in a PRS manikin. Hyperangulated blades may ensure a good and fast view of the vocal cords and low oral-soft-tissue-trauma but pose a challenge during the placement of the tube. Specific skills and handling seem to be necessary to ensure a safe tube placement with this sort of blades.
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- 2023
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14. Filamentous Algae Blooms in a Large, Clear-Water Lake: Potential Drivers and Reduced Benthic Primary Production
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Maycee Page, Tobias Goldhammer, Sabine Hilt, Scott Tolentino, and Soren Brothers
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periphyton ,Cladophora ,primary production ,climate change ,stable isotope analysis ,Bear Lake ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
An apparent proliferation of filamentous algal blooms (FABs) in pristine lakes around the world is a source of concern. However, little is known about the predominant drivers and effects of such FABs on lake ecosystems. We observed FABs in a large clear-water lake (Bear Lake, UT/ID, USA) and analyzed long-term lake monitoring data and algal stable isotopes for changes in climate, food webs and anthropogenic nutrient loading, respectively, as potential local drivers of FAB formation. Furthermore, we quantified in situ metabolism rates on rocks with and without FABs at two locations. Long-term monitoring data revealed increasing summer water temperatures (2009 to 2020) and decreasing winter ice cover (1923 to 2021). The FABs had δ15N values that were higher than 0 ‰, indicating a potential nutrient influx to Bear Lake from livestock or human waste. Climate change and anthropogenic nutrients may thus have facilitated FAB occurrence. Contrary to expectation, the FABs exhibited significantly lower gross primary production rates compared to low-biomass periphyton communities, indicating potentially negative effects of FAB proliferations on lake food webs. Our results highlight the need for expanding lake monitoring programs to include littoral zones to detect and mitigate changes occurring in lakes.
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- 2022
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15. Diurnal Changes in Hypoxia Shape Predator-Prey Interaction in a Bird-Fish System
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Juliane Lukas, Felix Auer, Tobias Goldhammer, Jens Krause, Pawel Romanczuk, Pascal Klamser, Lenin Arias-Rodriguez, and David Bierbach
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predator-prey interactions ,bird predation ,poeciliidae ,hypoxia ,hydrogen-sulfide ,Evolution ,QH359-425 ,Ecology ,QH540-549.5 - Abstract
Animals often face changing environments, and behavioral flexibility allows them to rapidly and adaptively respond to abiotic factors that vary more or less regularly. However, abiotic factors that affect prey species do not necessarily affect their predators. Still, the prey’s response might affect the predator indirectly, yet evidence from the wild for such a classical bottom-up effect of abiotic factors shaping several trophic levels remains sparse. In many aquatic environments, daily changes in oxygen concentrations occur frequently. When oxygen levels drop to hypoxic levels, many fishes respond with aquatic surface respiration (ASR), during which they obtain oxygen by skimming the upper, oxygenated surface layer. By increasing time at the surface, fish become more vulnerable to fish-eating birds. We explored these cascading effects in a sulfidic spring system that harbors the endemic sulphur molly (Poecilia sulphuraria) as prey species and several fish-eating bird species. Sulfide-rich springs pose harsh conditions as hydrogen sulfide (H2S) is lethal to most metazoans and reduces dissolved oxygen (DO). Field sampling during three daytimes indicated that water temperatures rose from morning to (after)noon, resulting in the already low DO levels to decrease further, while H2S levels showed no diurnal changes. The drop in DO levels was associated with a decrease in time spent diving in sulphur mollies, which corresponded with an increase in ASR. Interestingly, the laboratory-estimated threshold at which the majority of sulphur mollies initiate ASR (ASR50:
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- 2021
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16. The Challenges of Reconstructing Tropical Biodiversity With Sedimentary Ancient DNA: A 2200-Year-Long Metagenomic Record From Bwindi Impenetrable Forest, Uganda
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René Dommain, Morgan Andama, Molly M. McDonough, Natalia A. Prado, Tobias Goldhammer, Richard Potts, Jesús E. Maldonado, John Bosco Nkurunungi, and Michael G. Campana
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sedimentary ancient DNA ,tropical biodiversity ,DNA preservation ,sediment ,tropical swamp ,shotgun sequencing ,Evolution ,QH359-425 ,Ecology ,QH540-549.5 - Abstract
Sedimentary ancient DNA has been proposed as a key methodology for reconstructing biodiversity over time. Yet, despite the concentration of Earth’s biodiversity in the tropics, this method has rarely been applied in this region. Moreover, the taphonomy of sedimentary DNA, especially in tropical environments, is poorly understood. This study elucidates challenges and opportunities of sedimentary ancient DNA approaches for reconstructing tropical biodiversity. We present shotgun-sequenced metagenomic profiles and DNA degradation patterns from multiple sediment cores from Mubwindi Swamp, located in Bwindi Impenetrable Forest (Uganda), one of the most diverse forests in Africa. We describe the taxonomic composition of the sediments covering the past 2200 years and compare the sedimentary DNA data with a comprehensive set of environmental and sedimentological parameters to unravel the conditions of DNA degradation. Consistent with the preservation of authentic ancient DNA in tropical swamp sediments, DNA concentration and mean fragment length declined exponentially with age and depth, while terminal deamination increased with age. DNA preservation patterns cannot be explained by any environmental parameter alone, but age seems to be the primary driver of DNA degradation in the swamp. Besides degradation, the presence of living microbial communities in the sediment also affects DNA quantity. Critically, 92.3% of our metagenomic data of a total 81.8 million unique, merged reads cannot be taxonomically identified due to the absence of genomic references in public databases. Of the remaining 7.7%, most of the data (93.0%) derive from Bacteria and Archaea, whereas only 0–5.8% are from Metazoa and 0–6.9% from Viridiplantae, in part due to unbalanced taxa representation in the reference data. The plant DNA record at ordinal level agrees well with local pollen data but resolves less diversity. Our animal DNA record reveals the presence of 41 native taxa (16 orders) including Afrotheria, Carnivora, and Ruminantia at Bwindi during the past 2200 years. Overall, we observe no decline in taxonomic richness with increasing age suggesting that several-thousand-year-old information on past biodiversity can be retrieved from tropical sediments. However, comprehensive genomic surveys of tropical biota need prioritization for sedimentary DNA to be a viable methodology for future tropical biodiversity studies.
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- 2020
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17. Phylogenetic and Functional Diversity of Saprolegniales and Fungi Isolated from Temperate Lakes in Northeast Germany
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Hossein Masigol, Jason Nicholas Woodhouse, Pieter van West, Reza Mostowfizadeh-Ghalamfarsa, Keilor Rojas-Jimenez, Tobias Goldhammer, Seyed Akbar Khodaparast, and Hans-Peter Grossart
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freshwater ecosystems ,aquatic carbon cycling ,plant litter degradation ,humic substances production ,Saprolegnia ,Achlya ,Biology (General) ,QH301-705.5 - Abstract
The contribution of fungi to the degradation of plant litter and transformation of dissolved organic matter (humic substances, in particular) in freshwater ecosystems has received increasing attention recently. However, the role of Saprolegniales as one of the most common eukaryotic organisms is rarely studied. In this study, we isolated and phylogenetically placed 51 fungal and 62 Saprolegniales strains from 12 German lakes. We studied the cellulo-, lignino-, and chitinolytic activity of the strains using plate assays. Furthermore, we determined the capacity of 10 selected strains to utilize 95 different labile compounds, using Biolog FF MicroPlates™. Finally, the ability of three selected strains to utilize maltose and degrade/produce humic substances was measured. Cladosporium and Penicillium were amongst the most prevalent fungal strains, while Saprolegnia, Achlya, and Leptolegnia were the most frequent Saprolegniales strains. Although the isolated strains assigned to genera were phylogenetically similar, their enzymatic activity and physiological profiling were quite diverse. Our results indicate that Saprolegniales, in contrast to fungi, lack ligninolytic activity and are not involved in the production/transformation of humic substances. We hypothesize that Saprolegniales and fungi might have complementary roles in interacting with dissolved organic matter, which has ecological implications for carbon cycling in freshwater ecosystems.
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- 2021
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18. Unraveling the Importance of Polyphenols for Microbial Carbon Mineralization in Rewetted Riparian Peatlands
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Dominik Zak, Cyril Roth, Viktoria Unger, Tobias Goldhammer, Nathalie Fenner, Chris Freeman, and Gerald Jurasinski
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decomposition ,enzyme inhibition ,microbial activity ,peatland restoration ,Sphagnum ,tannins ,Environmental sciences ,GE1-350 - Abstract
There have been widespread attempts to rewet peatlands in Europe and elsewhere in the world to restore their unique biodiversity as well as their important function as nutrient and carbon sinks. However, changes in hydrological regime and therefore oxygen availability likely alter the abundance of enzyme-inhibiting polyphenolic compounds, which have been suggested as a “latch” preventing large amounts of carbon from being released into the atmosphere by microbial mineralization. In recent years, a variety of factors have been identified that appear to weaken that latch including not only oxygen, but also pH. In minerotrophic fens, it is unknown if long-term peat mineralization during decades of drainage and intense agricultural use causes an enrichment or a decline of enzyme-inhibiting polyphenols. To address this, we collected peat samples and fresh roots of dominating plants (i.e., the peat parent material) from the upper 20 cm peat layer in 5 rewetted and 6 natural fens and quantified total phenolic content as well as hydrolysable and condensed tannins. Polyphenols from less decomposed peat and living roots served partly as an internal standard for polyphenol analysis and to run enzyme inhibition tests. As hypothesized, we found the polyphenol content in highly decomposed peat to be eight times lower than in less decomposed peat, while condensed tannin content was 50 times lower in highly degraded peat. In addition, plant tissue polyphenol contents differed strongly between peat-forming plant species, with the highest amount found in roots of Carex appropinquata at 450 mg g−1 dry mass, and lowest in Sphagnum spp. at 39 mg g−1 dry mass: a 10-fold difference. Despite large and clear differences in peat and porewater chemistry between natural and rewetted sites, enzyme activities determined with Fluorescein diacetate (FDA) hydrolysis and peat degradation were not significantly correlated, indicating no simple linear relationship between polyphenol content and microbial activity. Still, samples with low contents of polyphenols and condensed tannins showed the highest microbial activities as measured with FDA.
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- 2019
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19. Early Microglia Activation Precedes Photoreceptor Degeneration in a Mouse Model of CNGB1-Linked Retinitis Pigmentosa
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Thomas Blank, Tobias Goldmann, Mirja Koch, Lukas Amann, Christian Schön, Michael Bonin, Shengru Pang, Marco Prinz, Michael Burnet, Johanna E. Wagner, Martin Biel, and Stylianos Michalakis
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retinitis pigmentosa ,retinal degeneration ,cyclic nucleotide-gated channel ,microglia ,innate immune response ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Retinitis pigmentosa (RP) denotes a family of inherited blinding eye diseases characterized by progressive degeneration of rod and cone photoreceptors in the retina. In most cases, a rod-specific genetic defect results in early functional loss and degeneration of rods, which is followed by degeneration of cones and loss of daylight vision at later stages. Microglial cells, the immune cells of the central nervous system, are activated in retinas of RP patients and in several RP mouse models. However, it is still a matter of debate whether activated microglial cells may be responsible for the amplification of the typical degenerative processes. Here, we used Cngb1−/− mice, which represent a slow degenerative mouse model of RP, to investigate the extent of microglia activation in retinal degeneration. With a combination of FACS analysis, immunohistochemistry and gene expression analysis we established that microglia in the Cngb1−/− retina were already activated in an early, predegenerative stage of the disease. The evidence available so far suggests that early retinal microglia activation represents a first step in RP, which might initiate or accelerate photoreceptor degeneration.
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- 2018
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20. Successful subretinal delivery and monitoring of MicroBeads in mice.
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M Dominik Fischer, Tobias Goldmann, Christine Wallrapp, Regine Mühlfriedel, Susanne C Beck, Gabi Stern-Schneider, Marius Ueffing, Uwe Wolfrum, and Mathias W Seeliger
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Medicine ,Science - Abstract
To monitor viability of implanted genetically engineered and microencapsulated human stem cells (MicroBeads) in the mouse eye, and to study the impact of the beads and/or xenogenic cells on retinal integrity.MicroBeads were implanted into the subretinal space of SV126 wild type mice using an ab externo approach. Viability of microencapsulated cells was monitored by noninvasive retinal imaging (Spectralis™ HRA+OCT). Retinal integrity was also assessed with retinal imaging and upon the end of the study by light and electron microscopy. The implanted GFP-marked cells encapsulated in subretinal MicroBeads remained viable over a period of up to 4 months. Retinal integrity and viability appeared unaltered apart from the focal damage due to the surgical implantation, GFAP upregulation, and opsin mistargeting in the immediate surrounding tissue.The accessibility for routine surgery and its immune privileged state make the eye an ideal target for release system implants for therapeutic substances, including neurotrophic and anti-angiogenic compounds or protein based biosimilars. Microencapsulated human stem cells (MicroBeads) promise to overcome limitations inherent with single factor release systems, as they are able to produce physiologic combinations of bioactive compounds.
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- 2013
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21. Role of Microglia in CNS Autoimmunity
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Tobias Goldmann and Marco Prinz
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Immunologic diseases. Allergy ,RC581-607 - Abstract
Multiple sclerosis (MS) is the most common autoimmune disease of the central nervous system (CNS) in the Western world. The disease is characterized histologically by the infiltration of encephalitogenic TH1/TH17-polarized CD4+ T cells, B cells, and a plethora of myeloid cells, resulting in severe demyelination ultimately leading to a degeneration of neuronal structures. These pathological processes are substantially modulated by microglia, the resident immune competent cells of the CNS. In this overview, we summarize the current knowledge regarding the highly diverse and complex function of microglia during CNS autoimmunity in either promoting tissue injury or tissue repair. Hence, understanding microglia involvement in MS offers new exciting paths for therapeutic intervention.
- Published
- 2013
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