Gold Open-Access
Refine
Year of publication
Document Type
- Article (2374)
- Review (84)
- Monograph/Edited Volume (73)
- Other (43)
- Part of Periodical (40)
- Conference Proceeding (29)
- Part of a Book (22)
- Master's Thesis (19)
- Doctoral Thesis (17)
- Report (12)
Language
- English (2088)
- German (587)
- Spanish (29)
- French (19)
- Multiple languages (4)
- Italian (3)
- Russian (3)
- Portuguese (2)
Keywords
- digital education (37)
- e-learning (37)
- MOOC (35)
- online course creation (33)
- online course design (33)
- Digitale Bildung (32)
- Kursdesign (32)
- Micro Degree (32)
- Online-Lehre (32)
- Onlinekurs (32)
Institute
- Institut für Biochemie und Biologie (413)
- Extern (368)
- Institut für Geowissenschaften (247)
- Institut für Physik und Astronomie (216)
- Institut für Romanistik (169)
- Institut für Umweltwissenschaften und Geographie (153)
- Historisches Institut (146)
- Hasso-Plattner-Institut für Digital Engineering GmbH (125)
- Department Sport- und Gesundheitswissenschaften (114)
- Institut für Ernährungswissenschaft (102)
We consider the emerging dynamics of a separable continuous time random walk (CTRW) in the case when the random walker is biased by a velocity field in a uniformly growing domain. Concrete examples for such domains include growing biological cells or lipid vesicles, biofilms and tissues, but also macroscopic systems such as expanding aquifers during rainy periods, or the expanding Universe. The CTRW in this study can be subdiffusive, normal diffusive or superdiffusive, including the particular case of a Lévy flight. We first consider the case when the velocity field is absent. In the subdiffusive case, we reveal an interesting time dependence of the kurtosis of the particle probability density function. In particular, for a suitable parameter choice, we find that the propagator, which is fat tailed at short times, may cross over to a Gaussian-like propagator. We subsequently incorporate the effect of the velocity field and derive a bi-fractional diffusion-advection equation encoding the time evolution of the particle distribution. We apply this equation to study the mixing kinetics of two diffusing pulses, whose peaks move towards each other under the action of velocity fields acting in opposite directions. This deterministic motion of the peaks, together with the diffusive spreading of each pulse, tends to increase particle mixing, thereby counteracting the peak separation induced by the domain growth. As a result of this competition, different regimes of mixing arise. In the case of Lévy flights, apart from the non-mixing regime, one has two different mixing regimes in the long-time limit, depending on the exact parameter choice: in one of these regimes, mixing is mainly driven by diffusive spreading, while in the other mixing is controlled by the velocity fields acting on each pulse. Possible implications for encounter–controlled reactions in real systems are discussed.
Empirical evidence of the relationship between social support and post-disaster mental health provides support for a general beneficial effect of social support (main-effect model; Wheaton, 1985). From a theoretical perspective, a buffering effect of social support on the negative relationship between disaster-related stress and mental health also seems plausible (stress-buffering model; Wheaton, 1985). Previous studies, however, (a) have paid less attention to the buffering effect of social support and (b) have mainly relied on interpersonal support (but not collective-level support such as community resilience) when investigating this issue. This previous work might have underestimated the effect of support on post-disaster mental health. Building on a sample of residents in Germany recently affected by flooding (N = 118), we show that community resilience to flooding (but not general interpersonal social support) buffered against the negative effects of flooding on post-disaster mental health. The results support the stress-buffering model and call for a more detailed look at the relationship between support and resilience and post-disaster adjustment, including collective-level variables.
Background: The regular assessment of hormonal and mood state parameters in professional soccer are proposed as good indicators during periods of intense training and/or competition to avoid overtraining.
Objective: The aim of this study was to analyze hormonal, psychological, workload and physical fitness parameters in elite soccer players in relation to changes in training and match exposure during a congested period of match play.
Methods: Sixteen elite soccer players from a team playing in the first Tunisian soccer league were evaluated three times (T1, T2, and T3) over 12 weeks. The non-congested period of match play was from T1 to T2, when the players played 6 games over 6 weeks. The congested period was from T2 to T3, when the players played 10 games over 6 weeks. From T1 to T3, players performed the Yo-Yo intermittent recovery test level 1 (YYIR1), the repeated shuttle sprint ability test (RSSA), the countermovement jump test (CMJ), and the squat jump test (SJ). Plasma Cortisol (C), Testosterone (T), and the T/C ratio were analyzed at T1, T2, and T3. Players had their mood dimensions (tension, depression, anger, vigor, fatigue, confusion, and a Total Mood Disturbance) assessed through the Profile of Mood State questionnaire (POMS). Training session rating of perceived exertion (sRPE) was also recorded on a daily basis in order to quantify internal training load and elements of monotony and strain.
Results: Significant performance declines (T1 < T2 < T3) were found for SJ performance (p = 0.04, effect size [ES] ES₁₋₂ = 0.15−0.06, ES₂₋₃ = 0.24) from T1 to T3. YYIR1 performance improved significantly from T1 to T2 and declined significantly from T2 to T3 (p = 0.001, ES₁₋₂ = 0.24, ES₂₋₃ = −2.54). Mean RSSA performance was significantly higher (p = 0.019, ES₁₋₂ = −0.47, ES₂₋₃ = 1.15) in T3 compared with T2 and T1. Best RSSA performance was significantly higher in T3 when compared with T2 and T1 (p = 0.006, ES₂₋₃ = 0.47, ES₁₋₂ = −0.56), but significantly lower in T2 when compared with to T1. T and T/C were significantly lower in T3 when compared with T2 and T1 (T: p = 0.03, ES₃₋₂ = −0.51, ES₃₋₁ = −0.51, T/C: p = 0.017, ES₃₋₂ = −1.1, ES₃₋₁ = −1.07). Significant decreases were found for the vigor scores in T3 when compared to T2 and T1 (p = 0.002, ES₁₋₂ = 0.31, ES₃₋₂ = −1.25). A significant increase was found in fatigue scores in T3 as compared to T1 and T2 (p = 0.002, ES₁₋₂ = 0.43, ES₂₋₃ = 0.81). A significant increase was found from T1 < T2 < T3 intension score (p = 0.002, ES₁₋₂ = 1.1, ES₂₋₃ = 0.2) and anger score (p = 0.03, ES₁₋₂ = 0.47, ES₂₋₃ = 0.33) over the study period. Total mood disturbance increased significantly (p = 0.02, ES₁₋₂ = 0.91, ES₂₋₃ = 1.1) from T1 to T3. Between T1-T2, significant relationships were observed between workload and changes in T (r = 0.66, p = 0.003), and T/C ratio (r = 0.62, p = 0.01). There were significant relationships between performance in RSSAbest and training load parameters (workload: r = 0.52, p = 0.03; monotony: r = 0.62, p = 0.01; strain: r = 0.62, p = 0.009). Between T2-T3, there was a significant relationship between Δ% of total mood disturbance and Δ% of YYIR1 (r = −0.54; p = 0.04), RSSAbest (r = 0.58, p = 0.01), SJ (r = −0,55, p = 0.01), T (r = 0.53; p = 0.03), and T/C (r = 0.5; p = 0.04).
Conclusion: An intensive period of congested match play significantly compromised elite soccer players’ physical and mental fitness. These changes were related to psychological but not hormonal parameters; even though significant alterations were detected for selected measures. Mood monitoring could be a simple and useful tool to determine the degree of preparedness for match play during a congested period in professional soccer.
The great auk was once abundant and distributed across the North Atlantic. It is now extinct, having been heavily exploited for its eggs, meat, and feathers. We investigated the impact of human hunting on its demise by integrating genetic data, GPS-based ocean current data, and analyses of population viability. We sequenced complete mitochondrial genomes of 41 individuals from across the species' geographic range and reconstructed population structure and population dynamics throughout the Holocene. Taken together, our data do not provide any evidence that great auks were at risk of extinction prior to the onset of intensive human hunting in the early 16th century. In addition, our population viability analyses reveal that even if the great auk had not been under threat by environmental change, human hunting alone could have been sufficient to cause its extinction. Our results emphasise the vulnerability of even abundant and widespread species to intense and localised exploitation.
Verwaltungsmodernisierung
(2020)
Die Modernisierung der öffentlichen Verwaltung hat sich längst zu einer Daueraufgabe entwickelt. In den Modernisierungsprozessen stehen derzeit zwei Segmente besonders im Fokus: Digitalisierung und Partizipation. Digitalisierung geht heute weit über die ursprünglich mit diesem Stichwort angesprochene Umwandlung analoger Daten in elektronische Datenformate hinaus. Die Programmatik der Digitalisierung zielt auf den möglichst umfassenden Einsatz elektronischer Informations- und Kommunikationstechniken zur Unterstützung, Beschleunigung, Rationalisierung und in Teilen auch Ersetzung von herkömmlichen Verwaltungsabläufen mit der Perspektive auf eine Transformation und Durchdringung sowohl des gesamten Verwaltungshandelns als auch der gesamten Verwaltungsorganisation. Demgegenüber meint Partizipation nach gängigem Verständnis die Beteiligung von Bürgern und anderen gesellschaftlichen Akteuren an politischen Willensbildungs- und Entscheidungsprozessen. In spezifisch administrativem Zusammenhang geht es vor allem um die Einbindung von Bürgern in Entscheidungsprozesse der Verwaltung und um die Aktivierung der Zivilgesellschaft, die Erschließung bürgerschaftlichen Engagements sowie gesellschaftlicher Ressourcen für die Erfüllung von Verwaltungsaufgaben – und dies alles mit dem Ziel einer Verbesserung der Legitimität und Qualität öffentlicher Verwaltung. Die beiden Modernisierungsansätze stehen nicht unverbunden nebeneinander. Vielmehr gehen sie nicht selten ineinander über. Beispiele dafür sind die Bereitstellung von Optionen zu elektronischer Stellung und Bearbeitung von Anträgen sowie von elektronischen Plattformen für die Bürgerpartizipation.
An diesen Themenfeldern der Verwaltungsmodernisierung setzt der Tagungsband an. Er dokumentiert den Gedankenaustausch über Digitalisierungs- und Partizipationsprozesse zwischen polnischen und deutschen Verwaltungsrechtswissenschaftlern auf einer Tagung, die im Dezember 2019 an der Universität Potsdam stattgefunden hat.
Narratives are shaping our understanding of the world. They convey values and norms and point to desirable future developments. In this way, they justify and legitimize political actions and social practices. Once a narrative has emerged and this world view is supported by broad societal groups, narratives can provide powerful momentum to trigger innovation and changes in the course of action. Narratives, however, are not necessarily based on evidence and precise categories, but can instead be vague and ambiguous in order to be acceptable and attractive to different actors. However, the more open and inclusive a narrative is, the less impact can be expected. We investigate whether there is a shared narrative in research for the sustainable economy and how this can be evaluated in terms of its potential societal impact. The paper carves out the visions for the future that have been underlying the research projects conducted within the German Federal Ministry of Education and Research (BMBF) funding programme "The Sustainable Economy". It then analyzes whether these visions are compatible with narratives dominating societal discourse on the sustainable economy, and concludes how the use of visions and narratives in research can contribute to fostering societal transformations.
Plasticity in metabolism underpins local responses to nitrogen in Arabidopsis thaliana populations
(2019)
Nitrogen (N) is central for plant growth, and metabolic plasticity can provide a strategy to respond to changing N availability. We showed that two local A. thaliana populations exhibited differential plasticity in the compounds of photorespiratory and starch degradation pathways in response to three N conditions. Association of metabolite levels with growth-related and fitness traits indicated that controlled plasticity in these pathways could contribute to local adaptation and play a role in plant evolution.
During the last few decades, the rapid separation of the Small Aral Sea from the isolated basin has changed its hydrological and ecological conditions tremendously. In the present study, we developed and validated the hybrid model for the Syr Darya River basin based on a combination of state-of-the-art hydrological and machine learning models. Climate change impact on freshwater inflow into the Small Aral Sea for the projection period 2007-2099 has been quantified based on the developed hybrid model and bias corrected and downscaled meteorological projections simulated by four General Circulation Models (GCM) for each of three Representative Concentration Pathway scenarios (RCP). The developed hybrid model reliably simulates freshwater inflow for the historical period with a Nash-Sutcliffe efficiency of 0.72 and a Kling-Gupta efficiency of 0.77. Results of the climate change impact assessment showed that the freshwater inflow projections produced by different GCMs are misleading by providing contradictory results for the projection period. However, we identified that the relative runoff changes are expected to be more pronounced in the case of more aggressive RCP scenarios. The simulated projections of freshwater inflow provide a basis for further assessment of climate change impacts on hydrological and ecological conditions of the Small Aral Sea in the 21st Century.
Recombinant adeno-associated viruses (rAAV) provide outstanding options for customization and superior capabilities for gene therapy. To access their full potential, facile genetic manipulation is pivotal, including capsid loop modifications. Therefore, we assessed capsid tolerance to modifications of the structural VP proteins in terms of stability and plasticity. Flexible glycine-serine linkers of increasing sizes were, at the genetic level, introduced into the 587 loop region of the VP proteins of serotype 2, the best studied AAV representative. Analyses of biological function and thermal stability with respect to genome release of viral particles revealed structural plasticity. In addition, insertion of the 29 kDa enzyme beta-lactamase into the loop region was tested with a complete or a mosaic modification setting. For the mosaic approach, investigation of VP2 trans expression revealed that a Kozak sequence was required to prevent leaky scanning. Surprisingly, even the full capsid modification with beta-lactamase allowed for the assembly of capsids with a concomitant increase in size. Enzyme activity assays revealed lactamase functionality for both rAAV variants, which demonstrates the structural robustness of this platform technology.
Colombia's agriculture, forestry and other land use sector accounts for nearly half of its total greenhouse gas (GHG) emissions. The importance of smallholder deforestation is comparatively high in relation to its regional counterparts, and livestock agriculture represents the largest driver of primary forest depletion. Silvopastoral systems (SPSs) are presented as agroecological solutions that synergistically enhance livestock productivity, improve local farmers' livelihoods and hold the potential to reduce pressure on forest conversion. The department of Caquetá represents Colombia's most important deforestation hotspot. Targeting smallholder livestock farms through survey data, in this work we investigate the GHG mitigation potential of implementing SPSs for smallholder farms in this region. Specifically, we assess whether the carbon sequestration taking place in the soil and biomass of SPSs is sufficient to offset the per-hectare increase in livestock GHG emissions resulting from higher stocking rates. To address these questions we use data on livestock population characteristics and historic land cover changes reported from a survey covering 158 farms and model the carbon sequestration occurring in three different scenarios of progressively-increased SPS complexity using the CO2 fix model. We find that, even with moderate tree planting densities, the implementation of SPSs can reduce GHG emissions by 2.6 Mg CO2e ha−1 yr−1 in relation to current practices, while increasing agriculture productivity and contributing to the restoration of severely degraded landscapes.
This article looks at Émile Zola’s novel cycle Les Rougon-Macquart and argues that it describes its subject, the Second Empire, as a warming climate tending toward climate catastrophe. Zola’s affinity to the notion of climate is shown to be linked to his poetic employment of the concept of ‘milieu’, inspired by Hippolyte Taine. Close readings of selected passages from the Rougon-Macquart are used to work out the climatic difference between ‘the old’ and ‘the new Paris’, and the process of warming that characterises the Second Empire. Octave Mouret’s department store holds a special place in the article, as it is analysed through what the article suggests calling a ‘meteorotopos’: a location of intensified climatic conditions that accounts for an increased interaction between human and non-human actors. The department store is also one of the many sites in the novel cycle that locally prefigure the ‘global’ climate catastrophe of Paris burning, in which the Second Empire perishes.
The actin cytoskeleton and its response to external chemical stimuli is fundamental to the mechano-biology of eukaryotic cells and their functions. One of the key players that governs the dynamics of the actin network is the motor protein myosin II. Based on a phase space embedding we have identified from experiments three phases in the cytoskeletal dynamics of starved Dictyostelium discoideum in response to a precisely controlled chemotactic stimulation. In the first two phases the dynamics of actin and myosin II in the cortex is uncoupled, while in the third phase the time scale for the recovery of cortical actin is determined by the myosin II dynamics. We report a theoretical model that captures the experimental observations quantitatively. The model predicts an increase in the optimal response time of actin with decreasing myosin II-actin coupling strength highlighting the role of myosin II in the robust control of cell contraction.
Tumor-associated macrophages (TAMs) promote tumor growth and metastasis by suppressing tumor immune surveillance. Herein, we provide evidence that the immunosuppressive phenotype of TAMs is controlled by long-chain fatty acid metabolism, specifically unsaturated fatty acids, here exemplified by oleate. Consequently, en-route enriched lipid droplets were identified as essential organelles, which represent effective targets for chemical inhibitors to block in vitro polarization of TAMs and tumor growth in vivo. In line, analysis of human tumors revealed that myeloid cells infiltrating colon cancer but not gastric cancer tissue indeed accumulate lipid droplets. Mechanistically, our data indicate that oleate-induced polarization of myeloid cells depends on the mammalian target of the rapamycin pathway. Thus, our findings reveal an alternative therapeutic strategy by targeting the pro-tumoral myeloid cells on a metabolic level.
Background. In horses and ponies numerous medical conditions are known to be linked with inflammation in different tissues, especially in the liver. Besides affecting other metabolic pathways such as the expression of certain interleukins (IL), inflammation is associated with stress of the endoplasmic reticulum (ER). In particular, ER stress leads to adaptive stress response and can be measured by several markers of inflammatory and stress signalling pathways, like nuclear factor kappa B (NF-kB). Objectives. To investigate lipopolysaccharide (LPS)-induced inflammatory reactions and their modulation in horses and ponies by feeding a polyphenol-rich supplement consisting of green tea and curcuma. Methods. In a cross-over study, 11 animals were allocated to either a placebo or a supplement group and supplemented with 10 g of a blend of green tea and curcuma extract (GCE) or a placebo (calcium carbonate) once daily. After 21 days of supplementation, all animals underwent a LPS challenge to induce moderate systemic inflammation. Blood samples and liver biopsies were taken at standardized time points: 24 hours before and 12 hours after LPS challenge. Inflammatory blood parameters such as serum amyloid A (SAA), haptoglobin and retinol binding protein 4 (RBP4) were measured in serum. Hepatic mRNA levels of selected markers of inflammation such as haptoglobin, tumor necrosis factor alpha (TNF-alpha), IL-1 beta, IL-6, cluster of differentiation 68 (CD68), fibroblast growth factor 21 (FGF-21), NF-kappa B, activating transcription factor 4 (ATF4) were quantified by RT-qPCR. In addition, liver biopsies were examined histologically for inflammatory alterations. Results. Blood markers of acute inflammatory response increased after LPS challenge. In the liver, the proinflammatory cytokine IL-1 beta showed significantly lower mRNA levels after LPS challenge in the supplemented group (P = 0.04) compared to the placebo group. Levels of the hepatic CD68 mRNA increased significantly in the placebo group (P = 0.04). There were no significant differences between supplemented and placebo groups concerning other markers of inflammation and markers of ER stress within the liver. The number of hepatic macrophages were not different after LPS challenge in both feeding groups. Conclusion. LPS was able to induce inflammation but seemed less suitable to induce ER stress in the horses and ponies. The polyphenol-rich supplement showed some potential to reduce inflammatory responses. Nevertheless, the supplementation did not exert an overall anti-inflammatory effect in horses and ponies.
BackgroundPachycladon cheesemanii is a close relative of Arabidopsis thaliana and is an allotetraploid perennial herb which is widespread in the South Island of New Zealand. It grows at altitudes of up to 1000m where it is subject to relatively high levels of ultraviolet (UV)-B radiation. To gain first insights into how Pachycladon copes with UV-B stress, we sequenced its genome and compared the UV-B tolerance of two Pachycladon accessions with those of two A. thaliana accessions from different altitudes.ResultsA high-quality draft genome of P. cheesemanii was assembled with a high percentage of conserved single-copy plant orthologs. Synteny analysis with genomes from other species of the Brassicaceae family found a close phylogenetic relationship of P. cheesemanii with Boechera stricta from Brassicaceae lineage I. While UV-B radiation caused a greater growth reduction in the A. thaliana accessions than in the P. cheesemanii accessions, growth was not reduced in one P. cheesemanii accession. The homologues of A. thaliana UV-B radiation response genes were duplicated in P. cheesemanii, and an expression analysis of those genes indicated that the tolerance mechanism in P. cheesemanii appears to differ from that in A. thaliana.ConclusionAlthough the P. cheesemanii genome shows close similarity with that of A. thaliana, it appears to have evolved novel strategies allowing the plant to tolerate relatively high UV-B radiation.
Both climate-change damages and climate-change mitigation will incur economic costs. While the risk of severe damages increases with the level of global warming (Dell et al., 2014; IPCC, 2014b, 2018; Lenton et al., 2008), mitigating costs increase steeply with more stringent warming limits (IPCC, 2014a; Luderer et al., 2013; Rogelj et al., 2015). Here, we show that the global warming limit that minimizes this century's total economic costs of climate change lies between 1.9 and 2 ∘C, if temperature changes continue to impact national economic growth rates as observed in the past and if instantaneous growth effects are neither compensated nor amplified by additional growth effects in the following years. The result is robust across a wide range of normative assumptions on the valuation of future welfare and inequality aversion. We combine estimates of climate-change impacts on economic growth for 186 countries (applying an empirical damage function from Burke et al., 2015) with mitigation costs derived from a state-of-the-art energy–economy–climate model with a wide range of highly resolved mitigation options (Kriegler et al., 2017; Luderer et al., 2013, 2015). Our purely economic assessment, even though it omits non-market damages, provides support for the international Paris Agreement on climate change. The political goal of limiting global warming to “well below 2 degrees” is thus also an economically optimal goal given above assumptions on adaptation and damage persistence.
Background/objective
Dry land-training (e.g., plyometric jump training) can be a useful mean to improve swimming performance. This study examined the effects of an 8-week plyometric jump training (PJT) program on jump and sport-specific performances in prepubertal female swimmers.
Methods
Twenty-two girls were randomly assigned to either a plyometric jump training group (PJTG; n = 12, age: 10.01 ± 0.57 years, maturity-offset = -1.50 ± 0.50, body mass = 36.39 ± 6.32 kg, body height = 146.90 ± 7.62 cm, body mass index = 16.50 ± 1.73 kg/m2) or an active control (CG; n = 10, age: 10.50 ± 0.28 years, maturity-offset = -1.34 ± 0.51, body mass = 38.41 ± 9.42 kg, body height = 143.60 ± 5.05 cm, body mass index = 18.48 ± 3.77 kg/m2). Pre- and post-training, tests were conducted for the assessment of muscle power (e.g., countermovement-jump [CMJ], standing-long-jump [SLJ]). Sport-specific-performances were tested using the timed 25 and 50-m front crawl with a diving-start, timed 25-m front crawl without push-off from the wall (25-m WP), and a timed 25-m kick without push-off from the wall (25-m KWP).
Results
Findings showed a significant main effect of time for the CMJ (d = 0.78), the SLJ (d = 0.91), 25-m front crawl test (d = 2.5), and the 25-m-KWP (d = 1.38) test. Significant group × time interactions were found for CMJ, SLJ, 25-m front crawl, 50-m front crawl, 25-m KWP, and 25-m WP test (d = 0.29–1.63) in favor of PJTG (d = 1.34–3.50). No significant pre-post changes were found for CG (p > 0.05).
Conclusion
In sum, PJT is effective in improving muscle power and sport-specific performances in prepubertal swimmers. Therefore, PJT should be included from an early start into the regular training program of swimmers.
Movement ecology aims to provide common terminology and an integrative framework of movement research across all groups of organisms. Yet such work has focused on unitary organisms so far, and thus the important group of filamentous fungi has not been considered in this context. With the exception of spore dispersal, movement in filamentous fungi has not been integrated into the movement ecology field. At the same time, the field of fungal ecology has been advancing research on topics like informed growth, mycelial translocations, or fungal highways using its own terminology and frameworks, overlooking the theoretical developments within movement ecology. We provide a conceptual and terminological framework for interdisciplinary collaboration between these two disciplines, and show how both can benefit from closer links: We show how placing the knowledge from fungal biology and ecology into the framework of movement ecology can inspire both theoretical and empirical developments, eventually leading towards a better understanding of fungal ecology and community assembly. Conversely, by a greater focus on movement specificities of filamentous fungi, movement ecology stands to benefit from the challenge to evolve its concepts and terminology towards even greater universality. We show how our concept can be applied for other modular organisms (such as clonal plants and slime molds), and how this can lead towards comparative studies with the relationship between organismal movement and ecosystems in the focus.
The Alpine orogen formed as a result of the collision between the Adriatic and European plates. Significant crustal heterogeneity exists within the region due to the long history of interplay between these plates, other continental and oceanic blocks in the region, and inherited crustal features from earlier orogenies. Deformation relating to the collision continues to the present day. Here, a seismically constrained, 3-D structural and density model of the lithosphere of the Alps and their respective forelands, derived from integrating numerous geoscientific datasets, was adjusted to match the observed gravity field. It is shown that the distribution of seismicity and deformation within the region correlates well to thickness and density changes within the crust, and that the present-day Adriatic crust is both thinner and denser (22.5 km, 2800 kg m(-3) ) than the European crust (27.5 km, 2750 kg m(-3)). Alpine crust derived from each respective plate is found to show the same trend, with zones of Adriatic provenance (Austro-Alpine unit and Southern Alps) found to be denser and those of European provenance (Helvetic zone and Tauern Window) to be less dense. This suggests that the respective plates and related terranes had similar crustal properties to the present-day ones prior to orogenesis. The model generated here is available for open-access use to further discussions about the crust in the region.
Starch and Glycogen Analyses
(2020)
For complex carbohydrates, such as glycogen and starch, various analytical methods and techniques exist allowing the detailed characterization of these storage carbohydrates. In this article, we give a brief overview of the most frequently used methods, techniques, and results. Furthermore, we give insights in the isolation, purification, and fragmentation of both starch and glycogen. An overview of the different structural levels of the glucans is given and the corresponding analytical techniques are discussed. Moreover, future perspectives of the analytical needs and the challenges of the currently developing scientific questions are included
Fehler fördern Entwicklung
(2020)
Emotionen und Gefühle von Lehrenden und Lernenden werden im Schullalltag bedauerlicherweise zu wenig berücksichtigt, obwohl die Forschung vielfältige Ergebnisse zum Einfluss von Emotionen auf die Lern- und Leistungsbereitschaft beigetragen hat. Allerdings fehlt es aktuell an tragfähigen Konzepten für die konkrete Nutzung und Umsetzung dieses Wissens in der Schule.
Frau Christine Walzer testet im Rahmen ihrer Arbeit die von Benjamin Apelojg entwickelte FELIX-App, die Emotionen und Bedürfnisse von Lerngruppen aufnimmt und spiegelt. Der Fokus wird auf eine Unterrichtstunde mit dem Schwerpunkt Lernen aus Fehlern gesetzt. Neben dem Zusammenhang zwischen provozierten Fehlern und Emotionen, soll insbesondere der Einsatz der FELIX-App analysiert werden. Hierzu wurde die FELIX-App in Biologie-Kursen eines Gymnasiums eingesetzt. Die Schüler*innen wurden neben einem Pre- und Postfragebogen direkt im Unterricht mit der Felix-App zu ihren Emotionen in bestimmten Lernkontexten befragt. Die Arbeit bietet sowohl eine vertiefte Auseinandersetzung mit dem Thema „Emotionen im schulischen Kontext“, als auch einen Einblick in das Konzept der prozessorientierten Didaktik und zeigt beispielhaft den Einsatz der FELIX-App. Die gewonnenen Ergebnisse sprechen sehr für eine weitere Einbindung von Emotions-orientierten Abfragen und für eine offenere Fehlerkultur im Unterricht.
Corporate Citizenship
(2020)
Corporate citizenship, which is firms’ societal engagement beyond customer and shareholder interests, is a prominent topic in management practice and has led to extensive research. This increased interest resulted in a complex and fragmented scholarly literature. In order to structure and map the field quantitatively, we conducted a temporal analysis of publications and citations, an analysis of the productivity of involved disciplines, an analysis of the productivity of publication forms including journal impact factors, an author productivity and citation analysis, a co-author analysis, an article citation analysis, an article co-citation analysis, and a keyword co-occurrence analysis. Results of these bibliometric analyses show that corporate citizenship research seems to have been in a phase of stagnation since 2014 and shows a rather low degree of interdisciplinarity. Papers are predominantly published in high impact journals. Authors show little collaboration with other researchers. Current research relates to other business ethics topics, addresses philosophical foundations, and starts to relate to human resource management and organization studies.
Climate change is affecting the rate of carbon cycling, particularly in the Arctic. Permafrost degradation through deeper thaw and physical disturbances results in the release of carbon dioxide and methane to the atmosphere and to an increase in lateral dissolved organic matter (DOM) fluxes. Whereas riverine DOM fluxes of the large Arctic rivers are well assessed, knowledge is limited with regard to small catchments that cover more than 40% of the Arctic drainage basin. Here, we use absorption measurements to characterize changes in DOM quantity and quality in a low Arctic (Herschel Island, Yukon, Canada) and a high Arctic (Cape Bounty, Melville Island, Nunavut, Canada) setting with regard to geographical differences, impacts of permafrost degradation, and rainfall events. We find that DOM quantity and quality is controlled by differences in vegetation cover and soil organic carbon content (SOCC). The low Arctic site has higher SOCC and greater abundance of plant material resulting in higher chromophoric dissolved organic matter (cDOM) and dissolved organic carbon (DOC) than in the high Arctic. DOC concentration and cDOM in surface waters at both sites show strong linear relationships similar to the one for the great Arctic rivers. We used the optical characteristics of DOM such as cDOM absorption, specific ultraviolet absorbance (SUVA), ultraviolet (UV) spectral slopes (S275-295), and slope ratio (SR) for assessing quality changes downstream, at base flow and storm flow conditions, and in relation to permafrost disturbance. DOM in streams at both sites demonstrated optical signatures indicative of photodegradation downstream processes, even over short distances of 2000 m. Flow pathways and the connected hydrological residence time control DOM quality. Deeper flow pathways allow the export of permafrost-derived DOM (i.e. from deeper in the active layer), whereas shallow pathways with shorter residence times lead to the export of fresh surface- and near-surface-derived DOM. Compared to the large Arctic rivers, DOM quality exported from the small catchments studied here is much fresher and therefore prone to degradation. Assessing optical properties of DOM and linking them to catchment properties will be a useful tool for understanding changing DOM fluxes and quality at a pan-Arctic scale.
Um auch die unbeabsichtigten Folgen ihrer Politik zu ermitteln, unternehmen Regierungen umfassende Gesetzesfolgenabschätzungen. Immer häufiger lassen sie sich dabei von unabhängigen Expertengremien kontrollieren. Doch: Wie erzielen diese Gremien Einfluss? Und welche Rolle spielen sie als Politikberater für Bürokratieabbau und bessere Rechtsetzung? Das Buch eröffnet neue Einblicke in die Entwicklungshistorie und Handlungsrealität der drei erfahrensten Normenkontrollräte in Europa. Vor dem Hintergrund unterschiedlicher Verwaltungskulturen werden die Ratstypen „Wachhund“, „Torwächter“ und „Kritischer Freund“ herausgearbeitet. Die Ergebnisse schärfen die politische und wissenschaftliche Debatte um die Leistungsfähigkeit von Normenkontrollräten.
The synthesis of chiral nanoporous carbons based on chiral ionic liquids (CILs) of amino acids as precursors is described. Such unique precursors for the carbonization of CILs yield chiral carbonaceous materials with high surface area (approximate to 620 m(2) g(-1)). The enantioselectivities of the porous carbons are examined by advanced techniques such as selective adsorption of enantiomers using cyclic voltammetry, isothermal titration calorimetry, and mass spectrometry. These techniques demonstrate the chiral nature and high enantioselectivity of the chiral carbon materials. Overall, we believe that the novel approach presented here can contribute significantly to the development of new chiral carbon materials that will find important applications in chiral chemistry, such as in chiral catalysis and separation and in chiral sensors. From a scientific point of view, the approach and results reported here can significantly deepen our understanding of chirality at the nanoscale and of the structure and nature of chiral nonporous materials and surfaces.
Eine Gruppe, gar eine innerlich verbundene Gemeinschaft, können Intellektuelle im Normalfall nur bilden, soweit sie von gleichem Denken und Wollen bewegt werden […]. Wo dagegen die von den Intellektuellen vertretenen Ansichten weit divergieren, da kann es nur unter sehr kritischen Umständen geschehen, daß die verschieden gearteten (sozialen, politischen, rechtlichen, kulturellen, religiösen) Standpunkte und Anliegen – auf Zeit – sich zusammenfinden […]. Das polemische Element, das kritischen Intellektuellen ja wesensmäßig zu eigen ist, bringt am ehesten eine gemeinsame Front zwischen ihnen zustande.
Deformation associated with plate convergence at subduction zones is accommodated by a complex system involving fault slip and viscoelastic flow. These processes have proven difficult to disentangle. The 2010 M-w 8.8 Maule earthquake occurred close to the Chilean coast within a dense network of continuously recording Global Positioning System stations, which provide a comprehensive history of surface strain. We use these data to assemble a detailed picture of a structurally controlled megathrust fault frictional patchwork and the three-dimensional rheological and time-dependent viscosity structure of the lower crust and upper mantle, all of which control the relative importance of afterslip and viscoelastic relaxation during postseismic deformation. These results enhance our understanding of subduction dynamics including the interplay of localized and distributed deformation during the subduction zone earthquake cycle.
The most severe flood events in Turkey were determined for the period 1960–2014 by considering the number of fatalities, the number of affected people, and the total economic losses as indicators. The potential triggering mechanisms (i.e., atmospheric circulations and precipitation amounts) and aggravating pathways (i.e., topographic features, catchment size, land use types, and soil properties) of these 25 events were analyzed. On this basis, a new approach was developed to identify the main influencing factor per event and to provide additional information for determining the dominant flood occurrence pathways for severe floods. The events were then classified through hierarchical cluster analysis. As a result, six different clusters were found and characterized. Cluster 1 comprised flood events that were mainly influenced by drainage characteristics (e.g., catchment size and shape); Cluster 2 comprised events aggravated predominantly by urbanization; steep topography was identified to be the dominant factor for Cluster 3; extreme rainfall was determined as the main triggering factor for Cluster 4; saturated soil conditions were found to be the dominant factor for Cluster 5; and orographic effects of mountain ranges characterized Cluster 6. This study determined pathway patterns of the severe floods in Turkey with regard to their main causal or aggravating mechanisms. Accordingly, geomorphological properties are of major importance in large catchments in eastern and northeastern Anatolia. In addition, in small catchments, the share of urbanized area seems to be an important factor for the extent of flood impacts. This paper presents an outcome that could be used for future urban planning and flood risk prevention studies to understand the flood mechanisms in different regions of Turkey.
This book features four essays that illuminate the relationship between American and Soviet film cultures in the 20th century.
The first essay emphasizes the structural similarities and dissimilarities of the two cultures. Both wanted to reach the masses. However, the goal in Hollywood was to entertain (and educate a little) and in Moscow to educate (and entertain a little).
Some films in the Soviet Union as well as in the United States were conceived as clear competition to one another – as the second essay demonstrates – and the ideological opponent was not shown from its most advantageous side.
The third essay shows how, in the 1980s, the different film cultures made it difficult for the Soviet director Andrei Konchalovsky to establish himself in the US, but nevertheless allowed him to succeed.
In the 1960s, a genre became popular that tells the story of the Russian Civil War using stylistic features of the Western: The Eastern. Its rise and decline are analyzed in the fourth essay.
In this report, we illustrate the considerable impact of researcher degrees of freedom with respect to exclusion of participants in paradigms with a learning element. We illustrate this empirically through case examples from human fear conditioning research, in which the exclusion of ‘non-learners’ and ‘non-responders’ is common – despite a lack of consensus on how to define these groups. We illustrate the substantial heterogeneity in exclusion criteria identified in a systematic literature search and highlight the potential problems and pitfalls of different definitions through case examples based on re-analyses of existing data sets. On the basis of these studies, we propose a consensus on evidence-based rather than idiosyncratic criteria, including clear guidelines on reporting details. Taken together, we illustrate how flexibility in data collection and analysis can be avoided, which will benefit the robustness and replicability of research findings and can be expected to be applicable to other fields of research that involve a learning element.
Alkylphospholipids are a novel class of antineoplastic drugs showing remarkable therapeutic potential. Among them, erufosine (EPC3) is a promising drug for the treatment of several types of tumors. While EPC3 is supposed to exert its function by interacting with lipid membranes, the exact molecular mechanisms involved are not known yet. In this work, we applied a combination of several fluorescence microscopy and analytical chemistry approaches (i.e., scanning fluorescence correlation spectroscopy, line-scan fluorescence correlation spectroscopy, generalized polarization imaging, as well as thin layer and gas chromatography) to quantify the effect of EPC3 in biophysical models of the plasma membrane, as well as in cancer cell lines. Our results indicate that EPC3 affects lipid–lipid interactions in cellular membranes by decreasing lipid packing and increasing membrane disorder and fluidity. As a consequence of these alterations in the lateral organization of lipid bilayers, the diffusive dynamics of membrane proteins are also significantly increased. Taken together, these findings suggest that the mechanism of action of EPC3 could be linked to its effects on fundamental biophysical properties of lipid membranes, as well as on lipid metabolism in cancer cells.
Stochastic models based on random diffusivities, such as the diffusing-diffusivity approach, are popular concepts for the description of non-Gaussian diffusion in heterogeneous media. Studies of these models typically focus on the moments and the displacement probability density function. Here we develop the complementary power spectral description for a broad class of random-diffusivity processes. In our approach we cater for typical single particle tracking data in which a small number of trajectories with finite duration are garnered. Apart from the diffusing-diffusivity model we study a range of previously unconsidered random-diffusivity processes, for which we obtain exact forms of the probability density function. These new processes are different versions of jump processes as well as functionals of Brownian motion. The resulting behaviour subtly depends on the specific model details. Thus, the central part of the probability density function may be Gaussian or non-Gaussian, and the tails may assume Gaussian, exponential, log-normal, or even power-law forms. For all these models we derive analytically the moment-generating function for the single-trajectory power spectral density. We establish the generic 1/f²-scaling of the power spectral density as function of frequency in all cases. Moreover, we establish the probability density for the amplitudes of the random power spectral density of individual trajectories. The latter functions reflect the very specific properties of the different random-diffusivity models considered here. Our exact results are in excellent agreement with extensive numerical simulations.
Farber disease is a rare lysosomal storage disorder resulting from acid ceramidase deficiency and subsequent ceramide accumulation. No treatments for Farber disease are clinically available, and affected patients have a severely shortened lifespan. We have recently reported a novel acid ceramidase deficiency model that mirrors the human disease closely. Acid sphingomyelinase is the enzyme that generates ceramide upstream of acid ceramidase in the lysosomes. Using our acid ceramidase deficiency model, we tested if acid sphingomyelinase could be a potential novel therapeutic target for the treatment of Farber disease. A number of functional acid sphingomyelinase inhibitors are clinically available and have been used for decades to treat major depression. Using these as a therapeutic for Farber disease, thus, has the potential to improve central nervous symptoms of the disease as well, something all other treatment options for Farber disease can’t achieve so far. As a proof-of-concept study, we first cross-bred acid ceramidase deficient mice with acid sphingomyelinase deficient mice in order to prevent ceramide accumulation. Double-deficient mice had reduced ceramide accumulation, fewer disease manifestations, and prolonged survival. We next targeted acid sphingomyelinase pharmacologically, to test if these findings would translate to a setting with clinical applicability. Surprisingly, the treatment of acid ceramidase deficient mice with the acid sphingomyelinase inhibitor amitriptyline was toxic to acid ceramidase deficient mice and killed them within a few days of treatment. In conclusion, our study provides the first proof-of-concept that acid sphingomyelinase could be a potential new therapeutic target for Farber disease to reduce disease manifestations and prolong survival. However, we also identified previously unknown toxicity of the functional acid sphingomyelinase inhibitor amitriptyline in the context of Farber disease, strongly cautioning against the use of this substance class for Farber disease patients.
Nature-based solutions (NBS) have recently received attention due to their potential ability to sustainably reduce hydro-meteorological risks, providing co-benefits for both ecosystems and affected people. Therefore, pioneering research has dedicated efforts to optimize the design of NBS, to evaluate their wider co-benefits and to understand promoting and/or hampering governance conditions for the uptake of NBS. In this article, we aim to complement this research by conducting a comprehensive literature review of factors shaping people’s perceptions of NBS as a means to reduce hydro-meteorological risks. Based on 102 studies, we identified six topics shaping the current discussion in this field of research: (1) valuation of the co-benefits (including those related to ecosystems and society); (2) evaluation of risk reduction efficacy; (3) stakeholder participation; (4) socio-economic and location-specific conditions; (5) environmental attitude, and (6) uncertainty. Our analysis reveals that concerned empirical insights are diverse and even contradictory, they vary in the depth of the insights generated and are often not comparable for a lack of a sound theoretical-methodological grounding. We, therefore, propose a conceptual model outlining avenues for future research by indicating potential inter-linkages between constructs underlying perceptions of NBS to hydro-meteorological risks.
The movement of microswimmers is often described by active Brownian particle models. Here we introduce a variant of these models with several internal states of the swimmer to describe stochastic strategies for directional swimming such as run and tumble or run and reverse that are used by microorganisms for chemotaxis. The model includes a mechanism to generate a directional bias for chemotaxis and interactions with external fields (e.g., gravity, magnetic field, fluid flow) that impose forces or torques on the swimmer. We show how this modified model can be applied to various scenarios: First, the run and tumble motion of E. coli is used to establish a paradigm for chemotaxis and investigate how it is affected by external forces. Then, we study magneto-aerotaxis in magnetotactic bacteria, which is biased not only by an oxygen gradient towards a preferred concentration, but also by magnetic fields, which exert a torque on an intracellular chain of magnets. We study the competition of magnetic alignment with active reorientation and show that the magnetic orientation can improve chemotaxis and thereby provide an advantage to the bacteria, even at rather large inclination angles of the magnetic field relative to the oxygen gradient, a case reminiscent of what is expected for the bacteria at or close to the equator. The highest gain in chemotactic velocity is obtained for run and tumble with a magnetic field parallel to the gradient, but in general a mechanism for reverse motion is necessary to swim against the magnetic field and a run and reverse strategy is more advantageous in the presence of a magnetic torque. This finding is consistent with observations that the dominant mode of directional changes in magnetotactic bacteria is reversal rather than tumbles. Moreover, it provides guidance for the design of future magnetic biohybrid swimmers. Author summary In this paper, we propose a modified Active Brownian particle model to describe bacterial swimming behavior under the influence of external forces and torques, in particular of a magnetic torque. This type of interaction is particularly important for magnetic biohybrids (i.e. motile bacteria coupled to a synthetic magnetic component) and for magnetotactic bacteria (i.e. bacteria with a natural intracellular magnetic chain), which perform chemotaxis to swim along chemical gradients, but are also directed by an external magnetic field. The model allows us to investigate the benefits and disadvantages of such coupling between two different directionality mechanisms. In particular we show that the magnetic torque can speed chemotaxis up in some conditions, while it can hinder it in other cases. In addition to an understanding of the swimming strategies of naturally magnetotactic organisms, the results may guide the design of future biomedical devices.
Intolerance to lactose or fructose is frequently diagnosed in children with chronic abdominal pain (CAP). However, the causal relationship remains a matter of discussion. A cohort of 253 patients, aged 7-12 years, presenting with unexplained CAP received standardized diagnostics. Additional diagnostic tests were performed based on their medical history and physical and laboratory investigations. Fructose and lactose hydrogen breath tests (H2BT) as well as empiric diagnostic elimination diets were performed in 135 patients reporting abdominal pain related to the consumption of lactose or fructose to evaluate carbohydrate intolerance as a potential cause of CAP. Carbohydrate malabsorption by H2BT was found in 55 (41%) out of 135 patients. An abnormal increase in H2BT was revealed in 30% (35/118) of patients after fructose consumption and in 18% (20/114) of patients after lactose administration. Forty-six percent (25/54) reported pain relief during a diagnostic elimination diet. In total, 17 patients had lactose malabsorption, 29 fructose malabsorption, and nine combined carbohydrate malabsorption. Carbohydrate intolerance as a cause of CAP was diagnosed at follow-up in only 18% (10/55) of patients with malabsorption after the elimination of the respective carbohydrate. Thus, carbohydrate malabsorption appears to be an incidental finding in children with functional abdominal pain disorders, rather than its cause. Therefore, testing of carbohydrate intolerance should only be considered in children with a strong clinical suspicion and with the goal to prevent long-term unnecessary dietary restrictions in children suffering from CAP.
Molecularly imprinted polymers (MIPs) mimic the binding sites of antibodies by substituting the amino acid-scaffold of proteins by synthetic polymers. In this work, the first MIP for the recognition of the diagnostically relevant enzyme butyrylcholinesterase (BuChE) is presented. The MIP was prepared using electropolymerization of the functional monomer o-phenylenediamine and was deposited as a thin film on a glassy carbon electrode by oxidative potentiodynamic polymerization. Rebinding and removal of the template were detected by cyclic voltammetry using ferricyanide as a redox marker. Furthermore, the enzymatic activity of BuChE rebound to the MIP was measured via the anodic oxidation of thiocholine, the reaction product of butyrylthiocholine. The response was linear between 50 pM and 2 nM concentrations of BuChE with a detection limit of 14.7 pM. In addition to the high sensitivity for BuChE, the sensor responded towards pseudo-irreversible inhibitors in the lower mM range.
Anti-Consumption
(2019)
Transcending the conventional debate around efficiency in sustainable consumption, anti-consumption patterns leading to decreased levels of material consumption have been gaining importance. Change agents are crucial for the promotion of such patterns, so there may be lessons for governance interventions that can be learnt from the every-day experiences of those who actively implement and promote sustainability in the field of anti-consumption. Eighteen social innovation pioneers, who engage in and diffuse practices of voluntary simplicity and collaborative consumption as sustainable options of anti-consumption share their knowledge and personal insights in expert interviews for this research. Our qualitative content analysis reveals drivers, barriers, and governance strategies to strengthen anti-consumption patterns, which are negotiated between the market, the state, and civil society. Recommendations derived from the interviews concern entrepreneurship, municipal infrastructures in support of local grassroots projects, regulative policy measures, more positive communication to strengthen the visibility of initiatives and emphasize individual benefits, establishing a sense of community, anti-consumer activism, and education. We argue for complementary action between top-down strategies, bottom-up initiatives, corporate activities, and consumer behavior. The results are valuable to researchers, activists, marketers, and policymakers who seek to enhance their understanding of materially reduced consumption patterns based on the real-life experiences of active pioneers in the field.
Melancholia
(2019)
Recent discovery of oxic methane production in sea and lake waters, as well as wetlands, demands re-thinking of the global methane cycle and re-assessment of the contribution of oxic waters to atmospheric methane emission. Here we analysed system-wide sources and sinks of surface-water methane in a temperate lake. Using a mass balance analysis, we show that internal methane production in well-oxygenated surface water is an important source for surface-water methane during the stratified period. Combining our results and literature reports, oxic methane contribution to emission follows a predictive function of littoral sediment area and surface mixed layer volume. The contribution of oxic methane source(s) is predicted to increase with lake size, accounting for the majority (>50%) of surface methane emission for lakes with surface areas >1 km(2).
The selection of a nest site is crucial for successful reproduction of birds. Animals which re-use or occupy nest sites constructed by other species often have limited choice. Little is known about the criteria of nest-stealing species to choose suitable nesting sites and habitats. Here, we analyze breeding-site selection of an obligatory "nest-cleptoparasite", the Amur Falcon Falco amurensis. We collected data on nest sites at Muraviovka Park in the Russian Far East, where the species breeds exclusively in nests of the Eurasian Magpie Pica pica. We sampled 117 Eurasian Magpie nests, 38 of which were occupied by Amur Falcons. Nest-specific variables were assessed, and a recently developed habitat classification map was used to derive landscape metrics. We found that Amur Falcons chose a wide range of nesting sites, but significantly preferred nests with a domed roof. Breeding pairs of Eurasian Hobby Falco subbuteo and Eurasian Magpie were often found to breed near the nest in about the same distance as neighboring Amur Falcon pairs. Additionally, the occurrence of the species was positively associated with bare soil cover, forest cover, and shrub patches within their home range and negatively with the distance to wetlands. Areas of wetlands and fallow land might be used for foraging since Amur Falcons mostly depend on an insect diet. Additionally, we found that rarely burned habitats were preferred. Overall, the effect of landscape variables on the choice of actual nest sites appeared to be rather small. We used different classification methods to predict the probability of occurrence, of which the Random forest method showed the highest accuracy. The areas determined as suitable habitat showed a high concordance with the actual nest locations. We conclude that Amur Falcons prefer to occupy newly built (domed) nests to ensure high nest quality, as well as nests surrounded by available feeding habitats.
MADS-box transcription factors (TFs) are ubiquitous in eukaryotic organisms and play major roles during plant development. Nevertheless, their function in seed development remains largely unknown. Here, we show that the imprinted Arabidopsis thaliana MADS-box TF PHERES1 (PHE1) is a master regulator of paternally expressed imprinted genes, as well as of non-imprinted key regulators of endosperm development. PHE1 binding sites show distinct epigenetic modifications on maternal and paternal alleles, correlating with parental-specific transcriptional activity. Importantly, we show that the CArG-box-like DNA-binding motifs that are bound by PHE1 have been distributed by RC/Helitron transposable elements. Our data provide an example of the molecular domestication of these elements which, by distributing PHE1 binding sites throughout the genome, have facilitated the recruitment of crucial endosperm regulators into a single transcriptional network.
Formaldehyde is a highly reactive compound that participates in multiple spontaneous reactions, but these are mostly deleterious and damage cellular components. In contrast, the spontaneous condensation of formaldehyde with tetrahydrofolate (THF) has been proposed to contribute to the assimilation of this intermediate during growth on C1 carbon sources such as methanol. However, the in vivo rate of this condensation reaction is unknown and its possible contribution to growth remains elusive. Here, we used microbial platforms to assess the rate of this condensation in the cellular environment. We constructed Escherichia coli strains lacking the enzymes that naturally produce 5,10-methylene-THF. These strains were able to grow on minimal medium only when equipped with a sarcosine (N-methyl-glycine) oxidation pathway that sustained a high cellular concentration of formaldehyde, which spontaneously reacts with THF to produce 5,10-methylene-THF. We used flux balance analysis to derive the rate of the spontaneous condensation from the observed growth rate. According to this, we calculated that a microorganism obtaining its entire biomass via the spontaneous condensation of formaldehyde with THF would have a doubling time of more than three weeks. Hence, this spontaneous reaction is unlikely to serve as an effective route for formaldehyde assimilation.
Engineering biotechnological microorganisms to use methanol as a feedstock for bioproduction is a major goal for the synthetic metabolism community. Here, we aim to redesign the natural serine cycle for implementation in E. coli. We propose the homoserine cycle, relying on two promiscuous formaldehyde aldolase reactions, as a superior pathway design. The homoserine cycle is expected to outperform the serine cycle and its variants with respect to biomass yield, thermodynamic favorability, and integration with host endogenous metabolism. Even as compared to the RuMP cycle, the most efficient naturally occurring methanol assimilation route, the homoserine cycle is expected to support higher yields of a wide array of products. We test the in vivo feasibility of the homoserine cycle by constructing several E. coli gene deletion strains whose growth is coupled to the activity of different pathway segments. Using this approach, we demonstrate that all required promiscuous enzymes are active enough to enable growth of the auxotrophic strains. Our findings thus identify a novel metabolic solution that opens the way to an optimized methylotrophic platform.
Background
Parasitoid wasps have fascinating life cycles and play an important role in trophic networks, yet little is known about their genome content and function. Parasitoids that infect aphids are an important group with the potential for biological control. Their success depends on adapting to develop inside aphids and overcoming both host aphid defenses and their protective endosymbionts.
Results
We present the de novo genome assemblies, detailed annotation, and comparative analysis of two closely related parasitoid wasps that target pest aphids: Aphidius ervi and Lysiphlebus fabarum (Hymenoptera: Braconidae: Aphidiinae). The genomes are small (139 and 141 Mbp) and the most AT-rich reported thus far for any arthropod (GC content: 25.8 and 23.8%). This nucleotide bias is accompanied by skewed codon usage and is stronger in genes with adult-biased expression. AT-richness may be the consequence of reduced genome size, a near absence of DNA methylation, and energy efficiency. We identify missing desaturase genes, whose absence may underlie mimicry in the cuticular hydrocarbon profile of L. fabarum. We highlight key gene groups including those underlying venom composition, chemosensory perception, and sex determination, as well as potential losses in immune pathway genes.
Conclusions
These findings are of fundamental interest for insect evolution and biological control applications. They provide a strong foundation for further functional studies into coevolution between parasitoids and their hosts. Both genomes are available at https://bipaa.genouest.org.
Germany and the United Kingdom have domestic shale gas reserves which they may exploit in the future to complement their national energy strategies. However gas production releases volatile organic compounds (VOC) and nitrogen oxides (NOx), which through photochemical reaction form ground-level ozone, an air pollutant that can trigger adverse health effects e.g. on the respiratory system. This study explores the range of impacts of a potential shale gas industry in these two countries on local and regional ambient ozone. To this end, comprehensive emission scenarios are used as the basis for input to an online-coupled regional chemistry transport model (WRF-Chem). Here we simulate shale gas scenarios over summer (June, July, August) 2011, exploring the effects of varying VOC emissions, gas speciation, and concentration of NOx emissions over space and time, on ozone formation. An evaluation of the model setup is performed, which exhibited the model’s ability to predict surface meteorological and chemical variables well compared with observations, and consistent with other studies. When different shale gas scenarios were employed, the results show a peak increase in maximum daily 8-hour average ozone from 3.7 to 28.3 μg m–3. In addition, we find that shale gas emissions can force ozone exceedances at a considerable percentage of regulatory measurement stations locally (up to 21% in Germany and 35% in the United Kingdom) and in distant countries through long-range transport, and increase the cumulative health-related metric SOMO35 (maximum percent increase of ~28%) throughout the region. Findings indicate that VOC emissions are important for ozone enhancement, and to a lesser extent NOx, meaning that VOC regulation for a future European shale gas industry will be of especial importance to mitigate unfavorable health outcomes. Overall our findings demonstrate that shale gas production in Europe can worsen ozone air quality on both the local and regional scales.
Identification and Characterization of Three Epithiospecifier Protein Isoforms in Brassica oleracea
(2019)
Glucosinolates present in Brassicaceae play a major role in herbivory defense. Upon tissue disruption, glucosinolates come into contact with myrosinase, which initiates their breakdown to biologically active compounds. Among these, the formation of epithionitriles is triggered by the presence of epithiospecifier protein (ESP) and a terminal double bond in the glucosinolate side chain. One ESP gene is characterized in the model plant Arabidopsis thaliana (AtESP; At1g54040.2). However, Brassica species underwent genome triplication since their divergence from the Arabidopsis lineage. This indicates the presence of multiple ESP isoforms in Brassica crops that are currently poorly characterized. We identified three B. oleracea ESPs, specifically BoESP1 (LOC106296341), BoESP2 (LOC106306810), and BoESP3 (LOC106325105) based on in silico genome analysis. Transcript and protein abundance were assessed in shoots and roots of four B. oleracea vegetables, namely broccoli, kohlrabi, white, and red cabbage, because these genotypes showed a differential pattern for the formation of glucosinolate hydrolysis products as well for their ESP activity. BoESP1 and BoESP2 were expressed mainly in shoots, while BoESP3 was abundant in roots. Biochemical characterization of heterologous expressed BoESP isoforms revealed different substrate specificities towards seven glucosinolates: all isoforms showed epithiospecifier activity on alkenyl glucosinolates, but not on non-alkenyl glucosinolates. The pH-value differently affected BoESP activity: while BoESP1 and BoESP2 activities were optimal at pH 6-7, BoESP3 activity remained relatively stable from pH 4 to 7. In order test their potential for the in vivo modification of glucosinolate breakdown, the three isoforms were expressed in A. thaliana Hi-0, which lacks AtESP expression, and analyzed for the effect on their respective hydrolysis products. The BoESPs altered the hydrolysis of allyl glucosinolate in the A. thaliana transformants to release 1-cyano-2,3-epithiopropane and reduced formation of the corresponding 3-butenenitrile and allyl isothiocyanate. Plants expressing BoESP2 showed the highest percentage of released epithionitriles. Given these results, we propose a model for isoform-specific roles of B. oleracea ESPs in glucosinolate breakdown.