68 research outputs found
Characterisation of a MAPKK kinase from <em>Craterostigma plantagineum</em> : Interaction of VIK kinases and LEA proteins
Drought is a key factor for yield loss in agriculture. However, desiccation tolerant plant species evolved various mechanisms to protect vegetative tissues from the hazardous effects of drought. These mechanisms are not fully understood and the work in this thesis contributes to the understanding of phosphorylation of stress related proteins in the desiccation tolerant plant Craterostigma plantagineum. In desiccation sensitive plant species MAPKKKs are known to be involved in multiple drought stress response pathways. However, their role in the acquisition of desiccation tolerance of resurrection plants has not been investigated up to now. In the desiccation tolerant plant species C. plantagineum several proteins show drought stress-dependent phosphorylation. The phosphorylation of these proteins was predicted to be partially mediated by MAPKKKs (Mariaux et al. 1998; Röhrig et al. 2006; Röhrig et al. 2008). An in-gel-kinase assay using the stress-related phosphoprotein CDeT11-24 as substrate demonstrated the presence of a MAPKKK in C. plantagineum (Petersen 2012). The identified MAPKKK is a homologue to the RAF-like MAPKKK VH1-interacting kinase (VIK) from A. thaliana (At1g14000) and was consequently named CpVIK. Based on this observation it was hypothesised that CpVIK and CDeT11-24 are functionally coupled and interact with each other. In this study in silico analyses demonstrated that CpVIK belongs to the tandem-repeat ankyrin motif containing MAPKKKs (ANKMAPKKKs) that are widely distributed in various taxa. Based on their early occurrence during evolution already in bacterial genomes and the conservation in plants as well as metazoa, it is assumed that the ANKMAPKKKs have essential functions which are not yet fully understood. Co-immunoprecipitation experiments performed in this work verified a physical interaction of CDeT11-24 and CpVIK. In vitro assays confirmed phosphorylation of CDeT11-24 by the enzymatic action of CpVIK. An increased expression of CpVIK on the RNA and protein level was observed upon abiotic stresses, including dehydration. Phosphorylation of the CpVIK protein revealed to be stress-dependent. CDeT11-24 and CpVIK showed to be co-expressed and the proteins are co-localised in the cytosol. Together with previous findings, showing high expression of VIK orthologs in seeds of desiccation sensitive species, it is proposed that VIK participates in the acquisition of drought tolerance in vegetative tissues of desiccation tolerant C. plantagineum as well as in seeds of desiccation sensitive plant species. In addition to an involvement of CpVIK in drought stress, for most VIK orthologous genes, an increase of gene expression in mature leaves compared to young leaves is observed indicating importance of VIK in later stages of plant development. In A. thaliana plants no phenotypic differences were detected for AtVIK knock-out mutant plants (Δvik) in comparison to wild type plants upon dehydration or salt stress at different developmental stages. However, a lower germination rate of Δvik seeds was observed especially under salt stress conditions. Comparative seed proteome analyses verified aberrant phosphoproteins in Δvik seeds including RD29B, the closest homologue to the CDeT11-24 LEA-like C. plantagineum protein. Mass spectrometric analyses demonstrated that five phosphorylation sites were absent in the RD29B protein extracted from Δvik seeds in comparison to wild type. This represents an in vivo evidence for a functional coupling of VIK and RD29B. This thesis demonstrated a correlation of VIK proteins with LEA proteins in C. plantagineum and A. thaliana. Identification of further downstream targets in seeds of Arabidopsis and vegetative tissue of C. plantagineum will contribute to the understanding of the mechanisms of desiccation tolerance
SPH propagation back-analysis of Baishuihe landslide in south-western China
Background Landslides and landslide dams are a major natural hazard causing high socioeconomic risk in inhabited mountainous areas. This is also true for vast parts of south-western China, which are highly prone to slope failures due to several factors, such as a humid climate with high precipitation in the summer months, geological predisposing factors with highly weathered sedimentary rocks and a high seismicity. In order to assess possible run-out distances and the potential of landslides to block rivers, it is crucial to understand which factors influence landslide propagation and how they can be quantified. Since it is often difficult or impossible to measure related geotechnical parameters in the field, their back analysis with a numerical modelling approach can be useful. In this study a numerical modelling analysis was implemented for the case of a complex landslide in south-western China, which transformed into a debris flow and blocked the river and a major road after heavy rainfall. For this purpose a quasi-3D smoothed particle hydrodynamics (SPH) model that can account for geotechnical slope parameters, run-out distance, velocities, and deposition heights was used. Based on field observations regarding initial landslide volume and final deposition volume, height, and length, the mechanical properties of the landslide were estimated in a back-analysis
Reply to: “Hysterectomy versus continuing conservative management: which is better for disseminated intravascular coagulation?”; Shinya Matsuzaki, MD, PhD, Yoshikazu Nagase, MD, Masayuki Endo, MD, PhD, Tadashi Kimura, MD, PhD
Purpose!#!Enzymes with epigenetic functions play an essential part in development of cancer. However, the significance of epigenetic changes in cervical carcinoma as a prognostic factor has not been fully investigated. Nuclear receptor corepressor (NCoR) presents itself as a potentially important element for epigenetic modification and as a potential prognostic aspect in cervical cancer.!##!Methods!#!By immunohistochemical staining of 250 tumor samples, the expression strength of NCoR was measured and evaluated by immunoreactive score (IRS) in the nucleus and cytoplasm.!##!Results!#!A low expression of NCoR in our patients was a disadvantage in overall survival. Expression of NCoR was negatively correlated with viral oncoprotein E6, acetylated histone H3 acetyl K9 and FIGO status, and positively correlated to p53.!##!Conclusions!#!Our study has identified epigenetic modification of tumor cells thus seems to be of relevance in cervical cancer as well for diagnosis, as a marker or as a potential therapeutic target in patients with advanced cervical carcinoma
The heating of dust by old stellar populations in the Bulge of M31
We use new Herschel multi-band imaging of the Andromeda galaxy to analyze how
dust heating occurs in the central regions of galaxy spheroids that are
essentially devoid of young stars. We construct a dust temperature map of M31
through fitting modified blackbody SEDs to the Herschel data, and find that the
temperature within 2 kpc rises strongly from the mean value in the disk of 17
pm 1K to \sim35K at the centre. UV to near-IR imaging of the central few kpc
shows directly the absence of young stellar populations, delineates the radial
profile of the stellar density, and demonstrates that even the near-UV dust
extinction is optically thin in M31's bulge. This allows the direct calculation
of the stellar radiation heating in the bulge, U\ast(r), as a function of
radius. The increasing temperature profile in the centre matches that expected
from the stellar heating, i.e. that the dust heating and cooling rates track
each other over nearly two orders of magnitude in U\ast. The modelled dust
heating is in excess of the observed dust temperatures, suggesting that it is
more than sufficient to explain the observed IR emission. Together with the
wavelength dependent absorption cross section of the dust, this demonstrates
directly that it is the optical, not UV, radiation that sets the heating rate.
This analysis shows that neither young stellar populations nor stellar near-UV
radiation are necessary to heat dust to warm temperatures in galaxy spheroids.
Rather, it is the high densities of Gyr-old stellar populations that provide a
sufficiently strong diffuse radiation field to heat the dust. To the extent
which these results pertain to the tenuous dust found in the centres of
early-type galaxies remains yet to be explored.Comment: 11 pages. Accepted for publication in MNRA
Traditional and modified Newmark displacement methods after the 2022 Ms 6.8 Luding earthquake (Eastern Tibetan Plateau)
peer reviewedThe Newmark displacement (ND) method, which reproduces the interactions between waves, solids, and fluids during an earthquake, has experienced numerous modifications. We compare the performances of a traditional and a modified version of the ND method through the analysis of co-seismic landslides triggered by the 2022 Ms 6.8 Luding earthquake (Sichuan, China). We implemented 23 ND scenarios with each equation, assuming different landslide depths, as well as various soil-rock geomechanical properties derived from previous studies in regions of similar lithology. These scenarios allowed verifying the presence or absence of such landslides and predict the likely occurrence locations. We evaluated the topographic and slope aspect amplification effects on both equations. The oldest equation has a better landslide predictive ability, as it considers both slope stability and earthquake intensity. Contrarily, the newer version of the ND method has a greater emphasis on slope stability compared to the earthquake intensity and hence tends to give high ND values only when the critical acceleration is weak. The topographic amplification does not improve the predictive capacity of these equations, most likely because few or no massive landslides were triggered from mountain peaks. This approach allows structural, focal mechanism, and site effects to be considered when designing ND models, which could help to explain and predict new landslide distribution patterns such as the abundance of landslides on the NE, E, S, and SE-facing slopes observed in the Luding case
Earthquake-induced landslides in Haiti: analysis of seismotectonic and possible climatic influences
peer reviewedAbstract. First analyses of landslide distribution and triggering factors
are presented for the region affected by the 14 August 2021 earthquake
(Mw=7.2) in the Nippes Department, Haiti. Landslide mapping was mainly
carried out by comparing pre- and post-event remote imagery (∼0.5–1 m resolution) available on Google Earth Pro® and
Sentinel-2 (10 m resolution) satellite images. The first covered about
50 % of the affected region (for post-event imagery and before completion
of the map in January 2022), and the latter were selected to cover the entire
potentially affected zone. On the basis of the completed landslide
inventory, comparisons are made with catalogs compiled by others both for
the August 2021 and the January 2010 seismic events, including one open
inventory (by the United States Geological Survey) that was also used for
further statistical analyses. Additionally, we studied the pre-2021
earthquake slope stability conditions. These comparisons show that the total
number of landslides mapped for the 2021 earthquake (7091) is larger than
the one recently published by another research team for the same event but
slightly smaller than the number of landslides mapped by a third research
team. It is also clearly smaller than the one observed by two other research
teams for the 2010 earthquake (e.g., 23 567, for the open inventory).
However, these apparently fewer landslides triggered in 2021 cover much
wider areas of slopes (>80 km2) than those induced by the
2010 event (∼25 km2 – considering the open inventory).
A simple statistical analysis indicates that the lower number of
2021 landslides can be explained by the missing detection of the smallest
landslides triggered in 2021, partly due to the lower-resolution imagery
available for most of the areas affected by the recent earthquake; this is
also confirmed by an inventory completeness analysis based on size–frequency
statistics. The much larger total area of landslides triggered in 2021,
compared to the 2010 earthquake, can be related to different physical
reasons: (a) the larger earthquake magnitude in 2021, (b) the more central
location of the fault segment that ruptured in 2021 with respect to coastal
zones, (c) and possible climatic preconditioning of slope instability in the
2021 affected area. These observations are supported by (1) a new pre-2021
earthquake landslide map; (2) rainfall distribution maps presented for
different periods (including October 2016 – when Hurricane Matthew had
crossed the western part of Haiti), covering both the 2010 and 2021 affected
zones; and (3) shaking intensity prediction maps
Roadmap für strombasierte Kraftstoffe 03EIV116A-G
Synthetische Kraftstoffe können die Defossilisierung des Verkehrssektors mit vorantreiben. Besonders bei hohen Transportvolumina oder für große Entfernungen sind diese Kraftstoffe eine vielversprechende Option, etwa in der Luft- und Schifffahrt oder zu Teilen im Schwerlastverkehr.
Auf Basis von Strom aus erneuerbaren Energien hergestellte Kraftstoffe sollen in Zukunft entscheidend dazu beitragen, die CO2-Bilanz zu verbessern und Klimaneutralität im Verkehrssektor zu erreichen. Die Forschung dockt damit an die Schnittstelle zwischen Energie- und Verkehrssektor an.
Im Rahmen der BMWK-Forschungsinitiative Energiewende im Verkehr (EiV) haben von 2018 bis 2023 insgesamt 16 industriegeführte F&E-Projekte die Entwicklung synthetischer Kraftstoffe für den Luft-, See- und Straßenverkehr deutlich vorangebracht. In den Projekten wurde eine Vielzahl verschiedener Kraftstoffe, Herstellverfahren und Anwendungen betrachtet. Dabei war es die Aufgabe der „Begleitforschung Energiewende im Verkehr“ (BEniVer), als einer der 16 EiV-Projektverbünde, die Projektergebnisse der technischen Forschungsvorhaben der Förderinitiative auf Basis eigenständiger wissenschaftlicher Analysen vergleichbar zu machen. Dazu wurden einheitliche Rahmenannahmen und Methodikleitfäden entwickelt.
Die Ergebnisse der Forschungsprojekte wurden in einer Gesamtbetrachtung zusammengeführt und dienten als Grundlage für technische, ökonomische und ökologische Bewertungen. Dabei beruhten die technologie-orientierten Bottom-Up-Analysen auf den neuesten Forschungsarbeiten. Diese wurden mit systemorientierten Top-Down-Analysen des Energie- und Verkehrssystems sowie möglichen Transformationspfaden auf dem Weg zur Klimaneutralität kombiniert. Weitere Analysen zur Akzeptanz und zur Markteinführung adressieren zudem gesellschaftliche Dimensionen und Auswirkungen der Einführung von strombasierten Kraftstoffen.
Auf Basis der ganzheitlichen Analysen wurden Schlussfolgerungen abgeleitet. Als Ergebnis der langjährigen und fachübergreifende Begleitung der EiV-Forschungsvorhaben ist mit der Roadmap für strombasierte Kraftstoffe ein Leitfaden entstanden mit Handlungsoptionen für die Erforschung, Entwicklung, Produktion und Markteinführung dieser Kraftstoffe
Forschungsinitiative Energiewende im Verkehr, Kurzbericht zur „Roadmap für strombasierte Kraftstoffe“ 03EIV116A-G
Synthetische Kraftstoffe können die Defossilisierung des Verkehrssektors mit vorantreiben. Besonders bei hohen Transportvolumina oder für große Entfernungen sind diese Kraftstoffe eine vielversprechende Option, etwa in der Luft- und Schifffahrt oder zu Teilen im Schwerlastverkehr.
Auf Basis von Strom aus erneuerbaren Energien hergestellte Kraftstoffe sollen in Zukunft entscheidend dazu beitragen, die CO2-Bilanz zu verbessern und Klimaneutralität im Verkehrssektor zu erreichen. Die Forschung dockt damit an die Schnittstelle zwischen Energie- und Verkehrssektor an.
Im Rahmen der BMWK-Forschungsinitiative Energiewende im Verkehr (EiV) haben von 2018 bis 2023 insgesamt 16 industriegeführte F&E-Projekte die Entwicklung synthetischer Kraftstoffe für den Luft-, See- und Straßenverkehr deutlich vorangebracht. In den Projekten wurde eine Vielzahl verschiedener Kraftstoffe, Herstellverfahren und Anwendungen betrachtet. Dabei war es die Aufgabe der „Begleitforschung Energiewende im Verkehr“ (BEniVer), als einer der 16 EiV-Projektverbünde, die Projektergebnisse der technischen Forschungsvorhaben der Förderinitiative auf Basis eigenständiger wissenschaftlicher Analysen vergleichbar zu machen. Dazu wurden einheitliche Rahmenannahmen und Methodikleitfäden entwickelt.
Die Ergebnisse der Forschungsprojekte wurden in einer Gesamtbetrachtung zusammengeführt und dienten als Grundlage für technische, ökonomische und ökologische Bewertungen. Dabei beruhten die technologie-orientierten Bottom-Up-Analysen auf den neuesten Forschungsarbeiten. Diese wurden mit systemorientierten Top-Down-Analysen des Energie- und Verkehrssystems sowie möglichen Transformationspfaden auf dem Weg zur Klimaneutralität kombiniert. Weitere Analysen zur Akzeptanz und zur Markteinführung adressieren zudem gesellschaftliche Dimensionen und Auswirkungen der Einführung von strombasierten Kraftstoffen.
Auf Basis der ganzheitlichen Analysen wurden Schlussfolgerungen abgeleitet. Als Ergebnis der langjährigen und fachübergreifende Begleitung der EiV-Forschungsvorhaben ist mit der Roadmap für strombasierte Kraftstoffe ein Leitfaden entstanden mit Handlungsoptionen für die Erforschung, Entwicklung, Produktion und Markteinführung dieser Kraftstoffe
Method development for the characterization of transport processes of engineered nanoparticles in saturated soils with focus on silver nanoparticles
With the growing amount of production and application of engineered nanoparticles, concerns are raising regarding the fate of the potentially toxic materials in the environment. In order to assess the potential of engineered nanoparticles for migration in soils and aquifers, an experimental study and subsequent mathematical modeling were carried out with the objective of the qualitative and quantitative description of the transport and deposition processes of engineered nanoparticles in water saturated soils. In column experiments the effect of physicochemical parameters, such as flow velocity and chemical composition of the soil solution on the transport and deposition behavior of the nanoparticles was examined in glass beads, a loamy sand soil and a silty loam soil. Flow field-flow fractionation (FlFFF) was implemented as a technique to characterize the nanoparticle samples prior to and after the soil passage, in order to detect the particle concentration and changes in the particle size distribution. For some selected experiments the distribution of nanoparticles deposited in the porous media columns was analyzed to obtain further information on the deposition behavior. With this experimental setup it was possible to produce reproducible data for engineered silver nanoparticles (AgNPs), while it failed for titanium dioxide nanoparticles (TiO2NPs), for which no reproducible measurements could be performed with FlFFF.The transport experiments showed that AgNPs were relatively mobile in glass beads and loamy sand at higher flow velocities and at low to medium concentrations of monovalent cations. The transport was strongly limited at lower flow velocities, which indicates the dominance of diffusion, the most relevant transport mechanism for particles < 1 μm, over advection at low flow velocities. At higher concentrations of monovalent cations or in the presence of divalent cations the transport of AgNPs in loamy sand was also strongly and at higher concentrations of divalent cations completely inhibited. This can be explained by the compression of the electrical double layer resulting in decreasing repulsive interactions between nanoparticles and soil surfaces. In silty loam no breakthrough of AgNPs could be observed, which can be explained by mechanical straining due to small pore size, enhanced physicochemical filtration due to increased specific surface area or the soil composition. While the transport behavior in loamy sand was almost conservative in the absence of cations, it showed a time dependent increase of the transport of AgNPs under all further experimental conditions, which manifested in a late and asymmetrical rise of the breakthrough curves. This observation was confirmed by the mathematical modeling and it can be related to the filling of a limited amount of attachment sites and the subsequent increase of the transport. The measurement of the particle size distribution of AgNPs before and after the transport experiments indicated in almost all cases a decrease of the particle size distribution after soil passage, suggesting the selective filtration of larger AgNPs.The results from the experiments and the mathematical modeling indicate the possible mobility of AgNPs in relatively coarsely grained porous media under certain conditions. Since these media are also relevant aquifer materials that play a role for drinking water supply in many regions of the world these conditions should be carefully investigated in future research
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