27 research outputs found
Scenarios for automated crop production
Der aktuelle technologische Fortschritt in der Landtechnik basiert auf dem zunehmenden Einsatz von Automatisierung. Erste Konzepte und Studien zu hochautomatisierten Systemen werden bereits erprobt und es gibt drei mögliche Ausgangssysteme für zukünftige Entwicklungen in der Landtechnik. Auf der einen Seite stehen der Traktor als universelle Großtechnik, aber auch der Selbstfahrer als prozessbezogene Großtechnik. Andererseits bietet der Roboter als Kleintechnik basierend auf neuen Technologien eine weitere Ausgangsbasis für zukünftige Entwicklungen. Für alle Maschinentypen gibt es viele Vor- und Nachteile sowie Initiatoren und Hemmnisse. Entscheidend für die weitere Erhöhung des Automatisierungsgrades ist vor allem die Möglichkeit einer vollständigen Prozessüberwachung und -bewertung. Die Frage, wie zukünftige Pflanzenbausysteme aussehen werden, steht in direktem Zusammenhang mit den technischen Möglichkeiten der Automatisierung und den Anforderungen der Pflanzen. Es werden Entwicklungspfade zur automatisierten Landtechnik betrachtet, die Unterschiede zwischen Kleintechnik und Großtechnik charakterisiert und das Potential für ein Kleintechnikszenario in Verbindung mit neuen Pflanzenbausystemen aufgezeigt.The current technological progress in agricultural engineering is based on the increasing use of automation. First concepts and studies of highly automated systems are already being tested and there are three potential starting platforms for future developments in agricultural engineering. On the one hand, there is the tractor as a universal large-scale technology, but also the self-propelled machine as a process-related large-scale technology. With the development of new technologies, the robot as a small-scale technology also offers a starting platform for future developments. Many advantages and disadvantages can be found for all platforms, as well as initiators and restraints. The crucial factor for further increasing the level of automation is above all the possibility of complete process monitoring and evaluation. The question of what future crop cultivation systems will look like is directly related to the technical possibilities of automation and the requirements of plants. Development paths for automated agricultural engineering will be considered, the differences between small and large-scale technology will be characterised and the potential for a small-scale technology scenario in connection with new crop cultivation systems will be described
Long-Term Behavior of Defined Mixed Cultures of Geobacter sulfurreducens and Shewanella oneidensis in Bioelectrochemical Systems
This work aims to investigate the long-term behavior of interactions of electrochemically active bacteria in bioelectrochemical systems. The electrochemical performance and biofilm characteristics of pure cultures of Geobacter sulfurreducens and Shewanella oneidensis are being compared to a defined mixed culture of both organisms. While S. oneidensis pure cultures did not form cohesive and stable biofilms on graphite anodes and only yielded 0.034 ± 0.011 mA/cm2 as maximum current density by feeding of each 5 mM lactate and acetate, G. sulfurreducens pure cultures formed 69 μm thick, area-wide biofilms with 10 mM acetate as initial substrate concentration and yielded a current of 0.39 ± 0.09 mA/cm2. Compared to the latter, a defined mixed culture of both species was able to yield 38% higher maximum current densities of 0.54 ± 0.07 mA/cm2 with each 5 mM lactate and acetate. This increase in current density was associated with a likewise increased thickness of the anodic biofilm to approximately 93 μm. It was further investigated whether a sessile incorporation of S. oneidensis into the mixed culture biofilm, which has been reported previously for short-term experiments, is long-term stable. The results demonstrate that S. oneidensis was not stably incorporated into the biofilm; rather, the planktonic presence of S. oneidensis has a positive effect on the biofilm growth of G. sulfurreducens and thus on current production
AgNPs Change Microbial Community Structures of Wastewater
Due to their strong antimicrobial activity, silver nanoparticles (AgNPs) are massively produced, applied, consumed and, as a negative consequence, released into wastewater treatment plants. Most AgNPs are assumed to be bound by sludge, and thus bear potential risk for microbial performance and stability. In this lab-scale study, flow cytometry as a high-throughput method and 16S rRNA gene amplicon Illumina MiSeq sequencing were used to track microbial community structure changes when being exposed to AgNPs. Both methods allowed deeper investigation of the toxic impact of chemicals on microbial communities than classical EC50 determination. In addition, ecological metrics were used to quantify microbial community variations depending on AgNP types (10 and 30 nm) and concentrations. Only low changes in α- and intra-community β-diversity values were found both in successive negative and positive control batches and batches that were run with AgNPs below the EC50 value. Instead, AgNPs at EC50 concentrations caused upcoming of certain and disappearance of formerly dominant subcommunities. Flavobacteriia were among those that almost disappeared, while phylotypes affiliated with Gammaproteobacteria (3.6-fold) and Bacilli (8.4-fold) increased in cell abundance in comparison to the negative control. Thus, silver amounts at the EC50 value affected community structure suggesting a potential negative impact on functions in wastewater treatment systems
The Activation of Mucosal-Associated Invariant T (MAIT) Cells Is Affected by Microbial Diversity and Riboflavin Utilization in vitro
Recent research has demonstrated that MAIT cells are activated by individual bacterial
or yeasts species that possess the riboflavin biosynthesis pathway. However, little
is known about the MAIT cell activating potential of microbial communities and the
contribution of individual community members. Here, we analyze the MAIT cell activating
potential of a human intestinal model community (SIHUMIx) as well as intestinal
microbiota after bioreactor cultivation. We determined the contribution of individual
SIHUMIx community members to the MAIT cell activating potential and investigated
whether microbial stress can influence their MAIT cell activating potential. The MAIT cell
activating potential of SIHUMIx was directly related to the relative species abundances
in the community. We therefore suggest an additive relationship between the species
abundances and their MAIT cell activating potential. In diverse microbial communities,
we found that a low MAIT cell activating potential was associated with high microbial
diversity and a high level of riboflavin demand and vice versa. We suggest that microbial
diversity might affect MAIT cell activation via riboflavin utilization within the community.
Microbial acid stress significantly reduced the MAIT cell activating potential of SIHUMIx
by impairing riboflavin availability through increasing the riboflavin demand.We show that
MAIT cells can perceive microbial stress due to changes in riboflavin utilization and that
riboflavin availability might also play a central role for the MAIT cell activating potential of
diverse microbiota
The Simplified Human Intestinal Microbiota (SIHUMIx) Shows High Structural and Functional Resistance against Changing Transit Times in In Vitro Bioreactors
Many functions in host–microbiota interactions are potentially influenced by intestinal
transit times, but little is known about the effects of altered transition times on the composition
and functionality of gut microbiota. To analyze these effects, we cultivated the model community
SIHUMIx in bioreactors in order to determine the effects of varying transit times (TT) on the
community structure and function. After five days of continuous cultivation, we investigated the
influence of different medium TT of 12 h, 24 h, and 48 h. For profiling the microbial community,
we applied flow cytometric fingerprinting and revealed changes in the community structure of
SIHUMIx during the change of TT, which were not associated with changes in species abundances.
For pinpointing metabolic alterations, we applied metaproteomics and metabolomics and found,
along with shortening the TT, a slight decrease in glycan biosynthesis, carbohydrate, and amino acid
metabolism and, furthermore, a reduction in butyrate, methyl butyrate, isobutyrate, valerate, and
isovalerate concentrations. Specifically, B. thetaiotaomicron was identified to be affected in terms of
butyrate metabolism. However, communities could recover to the original state afterward. This study
shows that SIHUMIx showed high structural stability when TT changed—even four-fold. Resistance
values remained high, which suggests that TTs did not interfere with the structure of the community
to a certain degree
Long-Term Behavior of Defined Mixed Cultures of Geobacter sulfurreducens and Shewanella oneidensis in Bioelectrochemical Systems
This work aims to investigate the long-term behavior of interactions of electrochemically active bacteria in bioelectrochemical systems. The electrochemical performance and biofilm characteristics of pure cultures of Geobacter sulfurreducens and Shewanella oneidensis are being compared to a defined mixed culture of both organisms. While S. oneidensis pure cultures did not form cohesive and stable biofilms on graphite anodes and only yielded 0.034 ± 0.011 mA/cm2 as maximum current density by feeding of each 5 mM lactate and acetate, G. sulfurreducens pure cultures formed 69 μm thick, area-wide biofilms with 10 mM acetate as initial substrate concentration and yielded a current of 0.39 ± 0.09 mA/cm2. Compared to the latter, a defined mixed culture of both species was able to yield 38% higher maximum current densities of 0.54 ± 0.07 mA/cm2 with each 5 mM lactate and acetate. This increase in current density was associated with a likewise increased thickness of the anodic biofilm to approximately 93 μm. It was further investigated whether a sessile incorporation of S. oneidensis into the mixed culture biofilm, which has been reported previously for short-term experiments, is long-term stable. The results demonstrate that S. oneidensis was not stably incorporated into the biofilm; rather, the planktonic presence of S. oneidensis has a positive effect on the biofilm growth of G. sulfurreducens and thus on current production
NASH limits anti-tumour surveillance in immunotherapy-treated HCC.
Hepatocellular carcinoma (HCC) can have viral or non-viral causes1-5. Non-alcoholic steatohepatitis (NASH) is an important driver of HCC. Immunotherapy has been approved for treating HCC, but biomarker-based stratification of patients for optimal response to therapy is an unmet need6,7. Here we report the progressive accumulation of exhausted, unconventionally activated CD8+PD1+ T cells in NASH-affected livers. In preclinical models of NASH-induced HCC, therapeutic immunotherapy targeted at programmed death-1 (PD1) expanded activated CD8+PD1+ T cells within tumours but did not lead to tumour regression, which indicates that tumour immune surveillance was impaired. When given prophylactically, anti-PD1 treatment led to an increase in the incidence of NASH-HCC and in the number and size of tumour nodules, which correlated with increased hepatic CD8+PD1+CXCR6+, TOX+, and TNF+ T cells. The increase in HCC triggered by anti-PD1 treatment was prevented by depletion of CD8+ T cells or TNF neutralization, suggesting that CD8+ T cells help to induce NASH-HCC, rather than invigorating or executing immune surveillance. We found similar phenotypic and functional profiles in hepatic CD8+PD1+ T cells from humans with NAFLD or NASH. A meta-analysis of three randomized phase III clinical trials that tested inhibitors of PDL1 (programmed death-ligand 1) or PD1 in more than 1,600 patients with advanced HCC revealed that immune therapy did not improve survival in patients with non-viral HCC. In two additional cohorts, patients with NASH-driven HCC who received anti-PD1 or anti-PDL1 treatment showed reduced overall survival compared to patients with other aetiologies. Collectively, these data show that non-viral HCC, and particularly NASH-HCC, might be less responsive to immunotherapy, probably owing to NASH-related aberrant T cell activation causing tissue damage that leads to impaired immune surveillance. Our data provide a rationale for stratification of patients with HCC according to underlying aetiology in studies of immunotherapy as a primary or adjuvant treatment
Plan, Repair, Execute, Explain — How Planning Helps to Assemble your Home Theater
In various social, work-related, or educational contexts, an increasing demand for intelligent assistance systems can be observed. In this paper, we present a domain-independent approach that combines a number of planning and interaction components to realize advanced user assistance. Based on a hybrid planning formalism, the components provide facilities including the generation, execution, and repair as well as the presentation and explanation of plans. We demonstrate the feasibility of our approach by means of a system that aims to assist users in the assembly of their home theater. An empirical evaluation shows the benefit of such a supportive system, in particular for persons with a lack of domain expertise