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The RNF/NQR redox pumps: a versatile system for energy transduction in bacteria and archaea
Full text linkThe Na + (or H + )-translocating ferredoxin:NAD + oxidoreductase (also called RNF, rhodobacter nitrogen fixation, complex) catalyzes the oxidation of reduced ferredoxin with NAD + , hereby generating an electrochemical gradient. In the reverse reaction driven by an electrochemical gradient, RNF provides reduced ferredoxin using NADH as electron donor. RNF plays a crucial role in the metabolism of many anaerobes, such as amino acid fermenters, acetogens, or aceticlastic methanogens. The Na + -translocating NADH:quinone oxidoreductase (NQR), which has evolved from an RNF, is found in selected bacterial groups including anaerobic, marine, or pathogenic organisms. Since NQR and RNF are not related to eukaryotic respiratory complex I (NADH:quinone oxidoreductase), members of this oxidoreductase family are promising targets for novel antibiotics. RNF and NQR share a membrane-bound core complex consisting of four subunits, which represent an essential functional module for redox-driven cation transport. Several recent 3D structures of RNF and NQR in different states put forward conformational coupling of electron transfer and Na + translocation reaction steps. Based on this common principle, putative reaction mechanisms of RNF and NQR redox pumps are compared.
Key points: • Electrogenic ferredoxin:NAD + oxidoreductases (RNF complexes) are found in bacteria and archaea. • The Na + -translocating NADH:quinone oxidoreductase (NQR) is evolutionary related to RNF. • The mechanism of energy conversion by RNF/NQR complexes is based on conformational coupling of electron transfer and cation transport reactions.Open Access funding enabled and organized by Projekt DEAL.Deutsche Forschungsgemeinschafthttps://doi.org/10.13039/501100001659Universität Hohenheim (3153
Analysis of acrylamide in vegetable chips after derivatization with 2-mercaptobenzoic acid by liquid chromatography–mass spectrometry
Full text linkSince many years, acrylamide (AA) is a well-known toxicologically relevant processing contaminant (“food-borne toxicant”). However, only during the recent years, high levels of acrylamide have been reported in vegetable chips. In the present study, AA was quantitated via a modified derivatization procedure with 2-mercaptobenzoic acid based on stable isotope dilution analysis and liquid chromatography–mass spectrometry. Extraction with a modified QuEChERS (quick, easy, cheap, efficient, rugged, safe) method, defatting with n -hexane, and a solid phase extraction clean-up with strong cation-exchange material were performed prior to the derivatization step. Limits of detection and quantitation (LoD and LoQ) were 12 and 41 µg of AA/kg of vegetable chips (estimated via signal-to-noise ratios of 3:1 and 10:1, respectively), and thus below the LoQ of 50 µg/kg requested by the European Food Safety Authority. Recovery rates between 92 and 101% at four spiking levels with a good precision expressed as a relative standard deviation < 7% were determined. With this method at hand, a survey of the current AA amounts in 38 vegetable chips from the worldwide market was performed, showing a remarkable variability between the different vegetables, but also between different products of the same vegetable. Thereby, the AA amounts ranged between 77.3 and 3090 µg/kg, with an average of 954 µg/kg which was distinctly higher in comparison to commercially available potato chips also analyzed in the present study (12 samples, range: 117–832 µg/kg, average: 449 µg/kg). While for sweet potato and parsnip relatively low AA amounts were found, beetroot and carrot showed rather high contents.Open Access funding enabled and organized by Projekt DEAL.Universität Hohenheim (3153
To move or not to move—factors influencing small-scale herder and livestock movements in the Dzungarian Gobi, Mongolia
No full textIn Mongolia, where nomadic pastoralism is still practiced by around one-third of the population, increasing livestock numbers, socio-economic constraints and climate change raise concerns over rangeland health. Little empirical evidence explains what triggers camp moves of pastoralists in the Dzungarian Gobi in Mongolia, which factors influence grazing mobility around camps, and how altitudinal migration benefits small livestock. We combined GPS tracking data of 19 small livestock herds monitored from September 2018 to April 2020 with remotely sensed climate and environmental data. We used general linear-mixed models to analyse variables influencing camp use duration and daily mobility patterns. To understand the importance of the altitudinal migration, we compared climatic conditions along the elevation gradient and looked at seasonal body weight changes of small livestock. We found that available plant biomass and season best explained camp use duration. Daily walking distance and maximum distance from camp increased with camp use duration. Pasture time increased with increasing biomass and rising temperatures. We conclude that herders in the Dzungarian Gobi have optimized pasture use by reacting to changes in biomass availability at landscape and local scale, and by embracing altitudinal migration. Flexibility in grazing mobility seems to have enabled local herder communities to practise sustainable pasture use. Maintaining this mobility will most likely be the best strategy to deal with environmental change under the current climate change scenarios.Open Access funding enabled and organized by Projekt DEAL.Heinrich Böll Stiftung http://dx.doi.org/10.13039/100009379International Takhi GroupNorges Forskningsråd http://dx.doi.org/10.13039/501100005416Universität Hohenheim (3153
Dairy byproducts as sustainable alternatives to FCS in 2D and 3D skeletal muscle cell cultures
No full textSkeletal muscle tissue engineering is a rapidly developing field with applications in disease modelling, tissue replacement, biorobotics, and cultivated meat. The need for more sustainable and ethical biotechnologies has grown due to concerns about resource scarcity, climate change, and animal welfare. One major challenge is replacing fetal calf serum (FCS), a widely used but ethically and environmentally highly problematic media supplement. A promising alternative is the utilization of natural byproducts such as whey and colostrum from the dairy industry, which provide essential nutrients and growth factors. In this study, wheys produced by microfiltration of raw milk and colostrum were investigated as FCS replacements for culturing C2C12 skeletal muscle cells. Composition analysis confirmed a variety of pro-proliferative compounds in both substances. Cell culture experiments led to the development of an optimized medium formulation based on colostrum whey. Colostrum whey medium (CM) supported cell proliferation and maintained the myogenic differentiation potential for over 30 days. Additionally, a CM-based freezing solution enabled effective cryopreservation throughout culture. In 3D static suspension culture, CM sustained viable spheroids for over 14 days. Spheroids showed significantly higher proliferation compared to those in serum-containing medium, making CM suitable for 3D modelling and scale-up of biomass production. These findings highlight CM as a sustainable, cost-effective, and ethical alternative for skeletal muscle tissue engineering, particularly in cultivated meat production
Unknown Germany - an integrative biodiversity discovery program
No full textBiodiversity knowledge, from genes to ecosystems, is crucial for addressing the biodiversity crisis. However, even in well-explored countries like Germany, much biodiversity remains unknown. Therefore, several research institutions are joining forces to conduct a comprehensive biodiversity inventory, combining broad taxonomic expertise with advanced technologies. By consolidating data across many organismic groups, the Unknown Germany initiative will significantly enhance conservation strategies and may serve as a model for similar efforts worldwide
EvaMol : A python tool for evaluating molecules in hit-to-lead optimization
Full text linkThis Python script was developed as a tool in structure-based drug discovery processes, such as fragment-to-lead-optimization, where a large number of variants of an initially identified hit molecule have to be evaluated and ranked in silico. The tool facilitates the identification and selection of follow-up drug candidates with improved predicted pharmacokinetic and binding properties. These candidates can derive from different procedures like similarity search or systematic chemical modifications. The initial hit data are provided either as coordinates of the protein-molecule complex obtained experimentally or by in silico methods such as docking making the script a versatile tool adaptable to variable workflows
Yield stability and weed dry matter in response to field-scale soil variability in pea-oat intercropping
Full text linkBackground and aims: Intercropping of grain legumes and cereals in European agriculture can provide benefits, such as an increase in yields, yield stability and weed suppression. Interactions between crops in intercropping may depend on spatial heterogeneity in soil conditions, which are present on farmers’ fields. Understanding the effect of within-field variation in soil conditions on interspecific interactions might increase the benefits of intercropping by within-field adjustment of the agronomic management. Methods: Crop performance and weed dry matter were assessed together with several soil properties in grids within three large field experiments at two sites (Germany and Sweden) and during two years. Each experiment was comprised of several strips sown either with the two sole crops oat ( Avena sativa L.) and field pea ( Pisum sativum L.) or an oat-pea intercrop. Results: The response of crop performance to within-field variability in soil conditions was mostly species-specific. Yield stability of intercropping was consistently higher compared with pea, but not compared to oat. The highest land equivalent ratio was found for an additive intercropping design under a higher water availability. In this experiment, yield stability of both intercropped pea and oat were lower, which might be expected as a result of within-field variation in interspecific interactions. Intercropping reduced weed dry matter compared to pea, for which one experiment indicated an increase in weed dry matter with nutrient availability. Conclusion: The experimental design and the developed statistical analysis can contribute to further research about spatial variations in interspecific interactions in intercropping, which will improve the understanding of plant-plant and plant-soil interactions.Open Access funding enabled and organized by Projekt DEAL.European Union’s Horizon 2020 Programme for Research & InnovationUniversität Hohenheim (3153
Markentransformation im Kontext der Servicetransformation
Full text linkIn der Literatur wurden Marken im Kontext der Servicetransformation noch nicht ausreichend untersucht. Darüber hinaus existiert nur wenig Forschung zu Goods-to-Service Markenerweiterungen und die bestehende Forschung betrachtet nicht den transformativen Charakter von Marken in der Servicetransformation. Damit stellt der Wandel von Marken im Kontext der Servicetransformation ein unerforschtes Thema dar.
Die kumulative Dissertation untersucht die Markentransformation im Kontext der Servicetransformation und entwickelt damit Konzepte für diese Forschungslücke. Die Arbeit ist in 5 Kapitel unterteilt: Kapitel 1 stellt die Einleitung dar und zeigt die Relevanz des Themas auf. Kapitel 2 bis 4 sind wissenschaftliche Beiträge, die in wissenschaftlichen Zeitschriften bzw. Sammelbänden eingereicht oder publiziert sind. Kapitel 5 umfasst die Schlussbetrachtung und gibt Implikationen auf Basis der Erkenntnisse der gesamten Arbeit.
In Kapitel 1 wird zunächst die Literatur zur Kundenperspektive der Servicetransformation dargestellt, da Marken maßgeblich durch die Kundenperspektive beeinflusst werden. Anschließend wird ein grundlegendes Verständnis für Markentransformationen geschaffen sowie die Literatur zu Marken in der Servicetransformation und zu Goods-to-Service Markenerweiterungen in einem Structured Literature Review analysiert. Abschließend werden die Ziele und Forschungsfragen der Arbeit aufgezeigt und der Gang der Untersuchung beschrieben.
Kapitel 2 konzipiert das theoretische Fundament der Dissertation. Zunächst wird ein dynamisches Markenverständnis aus der Literatur hergeleitet und darauf aufbauend die Markentransformation definiert. Dieses Konzept bildet eine zentrale Prämisse für die folgenden Kapitel. Anschließend wird die Markentransformation im Kontext der Servicetransformation betrachtet. Dabei werden drei Transformationsoptionen identifiziert: Rebranding, Markenerweiterungen und die Integration einer neuen Marke in die Markenarchitektur. Zudem wird das Markendynamiknetz entwickelt. Dieses erfasst alle Akteure und deren Interaktionen im Kontext der Marke und ermöglicht die Analyse von Veränderungen der Marke im Transformationsprozess. Abschließend wird ein Managementprozess aufgestellt und ein Ausblick gegeben.
Kapitel 3 erweitert das Konzept um die Kundenperspektive durch die Integration der Customer-Dominant Logic. Hierbei steht die Frage im Zentrum, welche Relevanz die Marke für Kunden hat, wenn sie den neuen Service eines Produktanbieters bewerten. Zu diesem Zweck wird die subjektive Markenwahrnehmung des Kunden mit der objektiven Perspektive des Markendynamiknetzes verknüpft. Dies erklärt, warum Kunden einer Marke bestimmte Eigenschaften zuschreiben. Anschließend wird die Customer-perceived Servitization Capability of a Brand (CSCB) als Eigenschaft einer Marke hergeleitet, um die kundenseitige Wahrnehmung der Servicetransformation nachzuvollziehen. Mit CSCB wird untersucht, warum Kunden einer Marke die Fähigkeit zur Servicetransformation zuschreiben. Zu diesem Zweck wurden 37 Tiefeninterviews (27 mit Kunden und zehn mit Experten) durchgeführt. Die Ergebnisse zeigen, dass Kunden zwischen Prozess- (Perceived Service Process Capability) und Ergebnisdimension (Perceived Service Outcome Capability) bei der Bewertung eines neuen Service einer Produktmarke unterscheiden. Zudem nutzen sie bisherige Markenerfahrungen als Servicesurrogate zur Bewertung von CSCB. Abschließend werden die Ergebnisse diskutiert und Implikationen abgeleitet.
Kapitel 4 fokussiert die strukturierte Konzeptualisierung und Operationalisierung von CSCB und der Servicesurrogate. Dazu wird die Literatur zu Perceived Capabilities, Markenerweiterungen und Servicetransformation analysiert. CSCB wird abgegrenzt und definiert. Die Zusammenhänge zwischen CSCB und den Servicesurrogaten werden literaturbasiert hergeleitet. Zur empirischen Prüfung werden Messinstrumente für CSCB und die Servicesurrogate entwickelt. Eine erste Validierung erfolgt durch einen Item Sorting Task mit Experten (n = 21). Anschließend wird die empirische Prüfung mit einer quantitativen Studie durchgeführt (n = 787). Die Ergebnisse zeigen den Einfluss der Servicesurrogate auf CSCB sowie dessen Relevanz für den Erfolg neuer Services einer Produktmarke. Schließlich werden die Ergebnisse diskutiert und Implikationen abgeleitet.
In Kapitel 5 erfolgt die Schlussbetrachtung. Die Ergebnisse der Kapitel 2 bis 4 werden holistisch betrachtet und die Forschungsfragen beantwortet. Zudem werden die Bedeutung der Studienergebnisse für die Markentransformation aufgezeigt und die Konzepte weiterentwickelt. Limitationen der Arbeit, Forschungs- und Praxisimplikationen sowie Maßnahmen für die Markentransformation im Kontext der Servicetransformation werden aufgezeigt.Brands in the context of servitization have not yet been sufficiently studied in the literature. Furthermore, there is little research on goods-to-service brand extensions and the existing research does not consider the transformative nature of brands in servitization. Thus, brand transformation in the context of servitization remains an under-researched field.
The cumulative dissertation examines brand transformation in the context of servitization and hence develops concepts for this research gap. The thesis is structured in 5 chapters: Chapter 1 provides the introduction and demonstrates the relevance of the research topic. Chapters 2 to 4 are scientific articles that have been submitted or published in scientific journals or anthologies. Chapter 5 comprises the concluding discussion and provides implications based on the findings of the entire thesis.
In chapter 1, the literature on customer perspective of servitization is reviewed, as brands are significantly affected by customer perspective. Subsequently, a general framework for brand transformations is established and the literature on brands in servitization as well as on goods-to-service brand extensions is analyzed in a structured literature review. Finally, the thesis' objectives and research questions are outlined and the course of the study is described.
Chapter 2 outlines the theoretical foundation of the dissertation. First, a dynamic understanding of brands is derived from the literature and, building on this, brand transformation is defined. This concept forms a core premise for the following chapters. Brand transformation is then considered in the context of servitization. Three transformation options are identified: Rebranding, brand extensions and the integration of a new brand into the brand architecture. Furthermore, the brand dynamics net is developed. It covers all actors and their interactions in the context of the brand and enables the analysis of changes of the brand in the transformation process. Finally, a management process is developed and an outlook is given.
Chapter 3 expands the concept with the customer perspective by integrating customer-dominant logic. The central question is what relevance the brand has for customers when they evaluate the new service of a product provider. For this purpose, the customer's subjective brand perception is linked with the objective perspective of the brand dynamics net. This explains why customers ascribe certain attributes to a brand. Subsequently, the Customer-perceived Servitization Capability of a Brand (CSCB) is derived as an attribute of a brand in order to understand customer's perception of servitization. CSCB is used to investigate why customers attribute the capability to servitize to a brand. For this purpose, 37 in-depth interviews (27 with customers and 10 with experts) were conducted. The results show that customers differentiate between the process dimension (Perceived Service Process Capability) and the outcome dimension (Perceived Service Outcome Capability) when evaluating a new service of a product brand. Moreover, they use previous brand experiences as service surrogates for the evaluation of CSCB. Finally, the results are discussed and implications are derived.
Chapter 4 focuses on the structured conceptualization and operationalization of CSCB and the service surrogates. The literature on perceived capabilities, brand extensions and servitization is analyzed for this purpose. CSCB is delineated and defined. The relationships between CSCB and the service surrogates are derived based on the literature. Measurement instruments for CSCB and the service surrogates are developed for empirical testing. An initial validation is provided by an item sorting task with experts (n = 21). The empirical testing is then conducted with a quantitative study (n = 787). The results show the influence of the service surrogates on CSCB as well as its relevance for the success of new services of a product brand. The findings are then discussed and implications are derived.
Chapter 5 contains the concluding discussion. The results of chapters 2 to 4 are considered holistically and the research questions are addressed. Furthermore, the significance of the study results for brand transformation is highlighted and the concepts are expanded. Limitations of the thesis, research and practical implications as well as measures for brand transformation in the context of servitization are presented
The tale of two Ions Na⁺ and Cl⁻: unraveling onion plant responses to varying salt treatments
Full text linkBackground: Exploring the adaptive responses of onions ( Allium cepa L.) to salinity reveals a critical challenge for this salt-sensitive crop. While previous studies have concentrated on the effects of sodium (Na⁺), this research highlights the substantial yet less-explored impact of chloride (Cl⁻) accumulation. Two onion varieties were subjected to treatments with different sodium and chloride containing salts to observe early metabolic responses without causing toxicity. Results: The initial effects of salinity on onions showed increased concentrations of both ions, with Cl⁻ having a more pronounced impact on metabolic profiles than Na⁺. Onions initially adapt to salinity by first altering their organic acid concentrations, which are critical for essential functions such as energy production and stress response. The landrace Birnförmige exhibited more effective regulation of its Na⁺/K⁺ balance and a milder response to Cl⁻ compared to the hybrid Hytech. Metabolic alterations were analyzed using advanced techniques, revealing specific responses in leaves and bulbs to Cl⁻ accumulation, with significant changes observed in organic acids involved in the TCA cycle, such as fumaric acid, and succinic acid, in both varieties. Additionally, there was a variety-specific increase in ethanolamine in Birnförmige and lysine in Hytech in response to Cl⁻ accumulation. Conclusion: This comprehensive study offers new insights into onion ion regulation and stress adaptation during the initial stages of salinity exposure, emphasizing the importance of considering both Na⁺ and Cl⁻ when assessing plant responses to salinity.Open Access funding enabled and organized by Projekt DEAL.Universität Hohenheim (3153
Motivational framing strategies in health care information security training: randomized controlled trial
Full text linkBackground: Information security is a critical challenge in the digital age, especially for hospitals, which are prime targets for cyberattacks due to the monetary worth of sensitive medical data. Given the distinctive security risks faced by health care professionals, tailored Security Education, Training, and Awareness (SETA) programs are needed to increase both their ability and willingness to integrate security practices into their workflows.
Objective: This study investigates the effectiveness of a video-based security training, which was customized for hospital settings and enriched with motivational framing strategies to build information security skills among health care professionals. The training stands out from conventional interventions in this context, particularly by incorporating a dual-motive model to differentiate between self- and other-oriented goals as stimuli for skill acquisition. The appeal to the professional values of responsible health care work, whether absent or present, facilitates a nuanced examination of differential framing effects on training outcomes.
Methods: A randomized controlled trial was conducted with 130 health care professionals from 3 German university hospitals. Participants within 2 intervention groups received either a self-oriented framing (focused on personal data protection) or an other-oriented framing (focused on patient data protection) at the beginning of a security training video. A control group watched the same video without any framing. Skill assessments using situational judgment tests before and after the training served to evaluate skill growth in all 3 groups.
Results: Members of the other-oriented intervention group, who were motivated to protect patients, exhibited the highest increase in security skills (ΔM=+1.13, 95% CI 0.82-1.45), outperforming both the self-oriented intervention group (ΔM=+0.55, 95% CI 0.24-0.86; P=.04) and the control group (ΔM=+0.40, 95% CI 0.10-0.70; P=.004). Conversely, the self-oriented framing of the training content, which placed emphasis on personal privacy, did not yield significantly greater improvements in security skills over the control group (mean difference=+0.15, 95% CI –0.69 to 0.38; P>.99). Further exploratory analyses suggest that the other-oriented framing was particularly impactful among participants who often interact with patients personally, indicating that a higher frequency of direct patient contact may increase receptiveness to this framing strategy.
Conclusions: This study underscores the importance of aligning SETA programs with the professional values of target groups, in addition to adapting these programs to specific contexts of professional action. In the investigated hospital setting, a motivational framing that resonates with health care professionals’ sense of responsibility for patient safety has proven to be effective in promoting skill growth. The findings offer a pragmatic pathway with a theoretical foundation for implementing beneficial motivational framing strategies in SETA programs within the health care sector