447 research outputs found
Development of a viscoelastic model of ice shelf dynamics
Climate Change has already caused large losses on natural occurring ice in the last decades and continues to do so. Antarctica, the largest source of land ice, contains an equivalent of several tens of meters of sea water level rise, which is induced not only by melting but also by out flow into ice shelves, the floating tongues of glaciers. In the last decades with recorded longer melt seasons and warming water in Antarctica, ice shelves are thinning and breaking up. With that, speed up of shelf inflowing glaciers are recorded, highlighting the buttressing force ice shelves have on glaciers and therefore their importance to the Antarctic Ice Sheet. Many factors play a role in the integrity of ice shelves, besides melting on the surface and from below, for example waves, tides and pressure imbalances at the calving front (buoyancy force) induce bending moments on short time scales. While ice is mainly studied as purely viscous, elastic or even plastic material. Certain ice shelf behaviour, like the tidal deformation near the grounding line or drainage of melt ponds, can only be sufficiently simulated with an viscoelastic model - representing the viscous thinning of ice as well as short term elastic bending deformations. Viscoelastic studies of ice so far have used commercial proprietary software, which require expensive licences and often lack inside in the used algorithms or flexibility to adapt the code as needed. In this thesis a viscoelastic model was developed in the open source FEM C++ environment Rheolef
Projecting invasive species using remote sensing and spatial explicit models
An evaluation of the current and previous Rosa rugosa growth on Kieler Ort, Germany, with the aim to predict the rose coverage in future, under consideration of environmental factors. Kieler Ort, a rather isolated island in the southwest Baltic Sea is representing a unique environment which is protected for its landscape, nature, flora and fauna and serves as a bird sanctuary. Rosa rugosa, as one of the most invasive non-native plant species along northern Europe’s coastline, was noted on the island and is therefore endangering the islands unique biotope. The previous and current extent of Rosa rugosa was retrieved from aerial images for the years 1994, 2000, 2007 and 2016. The 2016 outcome was validated by collecting ground truth data. A Rosa rugosa coverage of 10.6% was identified for 2016. An analysis of elevation, aspect and wind in relation to the Rosa rugosa locations on Kieler Ort showed an aversion to low, near sea level elevations. A Rosa rugosa preference of eastern-facing slopes was observed, which corresponded to wind protect aspects on the island. The Rosa rugosa coverage of the 4 years had been analyzed by comparing two adjacent years (3 periods). The overall area increase of Rosa rugosa had been estimated to 11.5% per annum. For the future prediction a cellular automata, as spatial explicit model, has been implemented; and predicted a Rosa rugosa coverage on Kieler Ort of 30.3% in 2036.Eine Bewertung des aktuellen und früheren Rosa rugosa Wachstums am Standort Kieler Ort, mit dem Ziel, die Rosenbedeckung in Zukunft vorhersagen zu können unter Berücksichtigung von Umweltfaktoren. Kieler Ort, eine eher abgelegene Insel in der südwestlichen Ostsee, repräsentiert eine einzigartige Umgebung, die für ihre Landschaft, Natur, Flora und Fauna geschützt ist und als Vogelschutzgebiet dient. Rosa rugosa, eine der invasivsten, nicht heimischen Pflanzenarten entlang der Küste Nordeuropas, wurde auf der Insel beobachtet und gefährdet somit das einzigartige Biotop der Inseln. Die frühere und aktuelle Ausdehnung von Rosa rugosa wurde aus Luftbildern für die Jahre 1994, 2000, 2007 und 2016 ermittelt. Das Ergebnis für 2016 wurde durch eine Begehung vor Ort validiert. Für das Jahr 2016 wurde eine Rosa rugosa Ausdehnung von 10,6% festgestellt. Eine Analyse von Höhelagen, Aspekten und Wind in Relation zu den Rosa rugosa Standorten auf Kieler Ort zeigte eine Abneigung gegen niedrige Höhen, nahe dem Meeresspiegelniveaus. Eine Rosa rugosa Präferenz zu Osthängen wurde beobachtet, was Windgeschützen Aspekten auf der Insel entsprach. Die Rosa rugosa Entwicklung über den genannten Zeitraum wurde analysiert durch Vergleich zweier benachbarter Jahre (3 Perioden). Der Gesamtflächenzuwachs von Rosa rugosa wurde auf 11,5% pro Jahr geschätzt. Für die Vorhersage wurde ein zellulärer Automat als räumliches explizites Modell implementiert; und prognostizierte eine Ausdehnung der Rosa rugosa auf Kieler Ort von 30,3% bei 2036.Rosa rugosa, also known as "potato rose", has its origins in Asia and was brought to Europe in the 19th century, where it shows a very invasive behavior in coastal regions. On Kieler Ort, a German isolated island in the south-west Baltic Sea, an increasing spread of this rose was found in recent years, which is why in this work, investigated the propagation speed and the current state of coverage on Kieler Ort with the aim of creating a forecast for the next 10 and 20 years. For the determination of the current state and the speed of growth, aerial photographs of the years 1994, 2000, 2007 and 2016 were digitized and analyzed. For validation an on-site inspection was performed on 3rd of November 2017. In 2016, more than 10% of the island was already covered by the rose and an average growth rate of 11.5% per year was determined, but the growth rate and rate of new shrubs between the investigated periods (1994-2000, 2000-2007, 2007-2016) varied a lot. An analysis showed that the Rosa rugosa grows on the island mainly in areas higher than 57cm above sea level, with Rosa rugosa being scarcely below 27cm above sea level and between 27-57cm an increase with height was seen. The study also showed that the rose grows preferably on east and south-east slopes (together 60% of all roses) and decreases in south, south-west, west and north-west slopes. For the 10 and 20 years forecast, a cellular automata - a spatially explicit modeling and simulation method - was implemented in Matlab. In addition to the growth rate and the island boundary, this also takes into account suitability in terms of elevation and slope aspect. For the calculation, the northern part of the island was excluded, due to the extensive changes of the island by erosion, which would distort the results. The 10 and 20 year forecasts were carried out with different growth rates according to the rates determined in the various periods, in order to determine a range in the forecast. For 2036, a rose coverage of 21.5% (2-period average) to 30.3% (3-period average) is expected. Since the new establishment in the model is likely to be underestimated due to terrain suitability, these values should be considered as lower estimates.Rosa rugosa, auch bekannt als „Kartoffel-Rose“, hat ihren Ursprung in Asien und wurde im 19. Jahrhundert nach Europa gebracht, wo sie ein sehr invasives Verhalten in Küstenregionen zeigt. Auf Kieler Ort, eine deute isolierte Insel in der südwestlichen Ostsee, wurde eine zunehmende Ausbreitung dieser Rose in den letzten Jahren festgestellt, weswegen in dieser Arbeit die Ausbreitungsgeschwindigkeit und der gegenwärtige Stand der Deckung auf Kieler Ort untersucht wurde mit dem Ziel eine Prognose für die nächsten 10 und 20 Jahre zu erstellen. Für die Ermittlung des gegenwärtigen Standes und der Wachstumsgeschwindigkeit wurden Luftbildaufnahmen der Jahre 1994, 2000, 2007 und 2016 digitalisiert und analysiert. Zur Validierung wurde am 3. November 2017 durch eine Begehung vor Ort durch gerührt. 2016 waren bereits über 10% der Insel durch die Rose bedeckt und eine durchschnittliche Wachstumsgeschwindigkeit von 11.5% pro Jahr wurde ermittelt, wobei die Wachstumsrate und Rate der neuen Büsche zwischen den untersuchten Perioden (1994-2000, 2000-2007, 2007-2016) sehr variiert. Eine durchgeführte Analyse zeigte das Rosa rugosa vornehmlich in Bereichen wächst die höher als 57cm über NN gelegen sind, wobei Rosa rugosa kaum unter 27cm über NN vorkommt und zwischen 27-57cm ein Anstieg des Vorkommens mit der Höhe vernommen wurde. Die Untersuchung zeigte außerdem das die Rose bevorzugt an Ost und Süd-Ost Hängen wächst (zusammen 60% aller Rosen) und vermindert an Süd, Süd-West, West und Nord-West Anstiegen. Für die 10 bzw. 20 Jahre Prognose wurde ein Zellulärer Automat – eine räumlich explizite Modelierungs- und Simulierungsmethode – in Matlab umgesetzt. Dieser berücksichtigt neben der Wachstumsrate und der Inselbegrenzung auch Geländetauglichkeit im Sinne von Höhenmodel und Neigungsaspekt. Für die Berechnung wurde der nördliche Teil der Insel ausgenommen, da auf Grund der umfangreichen Veränderungen der Insel durch Erosion, es zu Verfälschungen der Ergebnisse kommen würde. Die 10 und 20 Jahres Vorhersage wurde mit verschieden Wachstumsraten entsprechend der in den verschiedenen Zeiträumen ermittelten Raten durchgeführt um eine Spannweite in der Prognose zu ermitteln. Für 2036 werden Deckungen von 21,5% (2 Perioden Mittel) bis 30,3% (2 Perioden Mittel) erwartet. Da die Neuetablierung in dem Model aufgrund der Geländeeignung wahrscheinlich unterschätzt wurde, sind diese Werte als untere Schätzungen zu sehen
Exposure-response modeling improves selection of radiation and radiosensitizer combinations
A central question in drug discovery is how to select drug candidates from a large number of available compounds. This analysis presents a model-based approach for comparing and ranking combinations of radiation and radiosensitizers. The approach is quantitative and based on the previously-derived Tumor Static Exposure (TSE) concept. Combinations of radiation and radiosensitizers are evaluated based on their ability to induce tumor regression relative to toxicity and other potential costs. The approach is presented in the form of a case study where the objective is to find the most promising candidate out of three radiosensitizing agents. Data from a xenograft study is described using a nonlinear mixed-effects modeling approach and a previously-published tumor model for radiation and radiosensitizing agents. First, the most promising candidate is chosen under the assumption that all compounds are equally toxic. The impact of toxicity in compound selection is then illustrated by assuming that one compound is more toxic than the others, leading to a different choice of candidate
Digitalizing the Energy System in a Sustainable Way
The energy transition requires a restructuring of the energy system and, as a result of decentralisation, also increasing digitalisation to integrate all actors and make them more flexible. However, digitalisation can be shaped and should happen under ecological and social premises
Displaying and Experiencing Dress Identities in Museums: Case Studies from the Etruscan Period to Modern Times
Dress, clothes, and accessories receive and give meaning through their nearness to the human body. As P. Stallybrass writes: “Bodies come and go: the clothes that have received those bodies survive.” It is through the close interaction between dress and person that they both receive their meaning. Clothes shape the human body, and we in return shape our clothes. Dress communicates class, gender, nationality, and marital status, and we leave behind parts of us in its smell, wrinkles, wear, and tear: “Clothes receive the human imprint.” Archaeological and historical dress — no matter how ancient — remain intrinsically linked to their wearers. These are objects of use, affection, value, and memory, and through the study of the dress of past people, we may wear their habits and inhabit their spaces however briefly.
The visual appearance of people, in more recent times as well as throughout history, is a clear marker of identity and an important communication medium. For this reason, costume and jewelry serve as an “anchor point” to involve people of the 21st century in studies of the life of prehistoric and ancient societies. This is worth considering, as archaeological textile research needs a strong commitment to public outreach and education, as well as to be integrated into the challenges of our time and to participate in current debates. Through the lens of deep history, it can inspire people to think about such questions as identity, resource use, and shared heritage, among others. Dissemination of textiles and clothing for the broader public in museums is realized through various channels. These range from the exhibition of individual objects, such as textiles, garments, jewelry, and dress accessories, to virtual recreations, and encompasses workshops, citizen science projects for the recreation of historical garments, media-effective historical fashion shows, and reinterpretations of aspects of historical garments through contemporary fashion. This remains an ongoing process, since the interpretation of the past will never be complete, and every generation formulates new approaches. The EuroWeb COST Action (2020–2024) serves as an innovative hub to gain understanding of historical as well as recent dress identities. For this contribution, different aspects of the history of fashion from various museums have been selected as case studies, to demonstrate the wide span of possibilities for displaying and experiencing Dress Identities. Our journey starts with Etruscan jewelry as displayed at the Staatliche Antikensammlungen in Munich (Germany), leading to Early Medieval dress, recreated from various sources as a physical dress ensemble as well as a virtual one, and used for science communication at the Natural History Museum Vienna (Austria) and Halle an der Saale (Germany). As both of the first examples derive from archaeological contexts, we do not have complete garments. This was why we also wanted to explore the possibilities for dissemination of “folk historic costumes”, like a traditional mourning dress as displayed at the Museum Amager (Denmark)
Layer-specific distribution and expression pattern of AMPA- and NMDA-type glutamate receptors in the barrel field of the adult rat somatosensory cortex:a quantitative electron microscopic analysis
AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) and NMDA (N-methyl-d-aspartate) glutamate receptors are driving forces for synaptic transmission and plasticity at neocortical synapses. However, their distribution pattern in the adult rat neocortex is largely unknown and was quantified using freeze fracture replication combined with postimmunogold-labeling. Both receptors were co-localized at layer (L)4 and L5 postsynaptic densities (PSDs). At L4 dendritic shaft and spine PSDs, the number of gold grains detecting AMPA was similar, whereas at L5 shaft PSDs AMPA-receptors outnumbered those on spine PSDs. Their number was significantly higher at L5 vs. L4 PSDs. At L4 and L5 dendritic shaft PSDs, the number of gold grains detecting GluN1 was ~2-fold higher than at spine PSDs. The number of gold grains detecting the GluN1-subunit was higher for both shaft and spine PSDs in L5 vs. L4. Both receptors showed a large variability in L4 and L5. A high correlation between the number of gold grains and PSD size for both receptors and targets was observed. Both receptors were distributed over the entire PSD but showed a layer- and target-specific distribution pattern.The layer- and target-specific distribution of AMPA and GluN1 glutamate receptors partially contribute to the observed functional differences in synaptic transmission and plasticity in the neocortex
Theoretical and Methodological Framework for the Development of Urban Climatic Planning Recommendation Maps
Urban climatic analyses and planning recommendation maps are becoming increasingly important in the climate-sensitive planning of cities. Urban climatic maps typically include two main components (Ren et al. 2012): an urban climatic analysis map and an urban climatic planning recommendation map. Given the urgent need for action due to climatic changes in urban areas, planning recommendation maps are essential for introducing and locating measures that effectively increase the adaptive capacity of cities, thus increasing the resilience of urban areas and their inhabitants (BaumĂĽller 2015). The first urban climatic maps were produced in Germany in the 1970s and currently they are used worldwide.
The aim of this contribution is to develop a theoretical and methodological framework for the development of urban climatic planning recommendation maps. The main focus is on the review of existing theories and methods that serves as a roadmap for developing these maps. The examples show that these analyses usually consist of four steps or four areas of processing: (i) an urban climatic analysis, (ii) additional in-depth analyses, (iii) the development and location of measures and (iv) the consolidation in a planning information map (Ren et al. 2011).
Within the urban climatic analysis two main approaches are common: pure static GIS (Geographic Information System) derived maps or mainly meteorologically focused maps including the calculation of regional climate simulations (and hybrid forms thereof). Supplementary in-depth analyses are often carried out, such as the intersection with socio-demographic data to identify areas that are particularly vulnerable from a social point of view, or analyses based on specific urban or spatial configurations (Reisinger et al. 2020). In the third step of the process, measures are usually developed at different levels or for different sectors of urban development. As a final step, the results are summarised in planning recommendation maps and the measures are spatially located (BaumĂĽller 2015). Each of these individual steps has been intensively researched in the last few years; the synopsis or bringing together of these numerous research projects and approaches is a gap that this contribution seeks to fill.
The contribution demonstrates available approaches, methods and tools necessary to translate scientific climatic knowledge into urban planning recommendation maps, considering that the analyses for a particular city or municipality are strongly limited in reproducibility to other citys, even in the same country. Based on this, a theoretical and methodological framework for the development of urban climatic planning recommendation maps is elaborated that enables the creation of these
Overcoming hypoxia-induced tumor radioresistance in non-small cell lung cancer by targeting DNA-dependent protein kinase in combination with carbon ion irradiation
Background: Hypoxia-induced radioresistance constitutes a major obstacle for a curative treatment of cancer. The aim of this study was to investigate effects of photon and carbon ion irradiation in combination with inhibitors of DNA-Damage Response (DDR) on tumor cell radiosensitivity under hypoxic conditions.
Methods: Human non-small cell lung cancer (NSCLC) models, A549 and H1437, were irradiated with dose series of photon and carbon ions under hypoxia (1% O2) vs. normoxic conditions (21% O2). Clonogenic survival was studied after dual combinations of radiotherapy with inhibitors of DNA-dependent Protein Kinase (DNAPKi, M3814) and ATM serine/threonine kinase (ATMi).
Results: The OER at 30% survival for photon irradiation of A549 cells was 1.4. The maximal oxygen effect measured as survival ratio was 2.34 at 8Â Gy photon irradiation of A549 cells. In contrast, no significant oxygen effect was found after carbon ion irradiation. Accordingly, the relative effect of 6Â Gy carbon ions was determined as 3.8 under normoxia and. 4.11 under hypoxia. ATM and DNA-PK inhibitors dose dependently sensitized tumor cells for both radiation qualities. For 100Â nM DNAPKi the survival ratio at 4Â Gy more than doubled from 1.59 under normoxia to 3.3 under hypoxia revealing a strong radiosensitizing effect under hypoxic conditions. In contrast, this ratio only moderately increased after photon irradiation and ATMi under hypoxia. The most effective treatment was combined carbon ion irradiation and DNA damage repair inhibition.
Conclusions: Carbon ions efficiently eradicate hypoxic tumor cells. Both, ATMi and DNAPKi elicit radiosensitizing effects. DNAPKi preferentially sensitizes hypoxic cells to radiotherapy
The herpesviral Fc receptor fcr-1 down-regulates the NKG2D ligands MULT-1 and H60
Members of the α- and β-subfamily of herpesviridae encode glycoproteins that specifically bind to the Fc part of immunoglobulin (Ig)G. Plasma membrane resident herpesviral Fc receptors seem to prevent virus-specific IgG from activating antibody-dependent effector functions. We show that the mouse cytomegalovirus (MCMV) molecule fcr-1 promotes a rapid down-regulation of NKG2D ligands murine UL16-binding protein like transcript (MULT)-1 and H60 from the cell surface. Deletion of the m138/fcr-1 gene from the MCMV genome attenuates viral replication to natural killer (NK) cell response in an NKG2D-dependent manner in vivo. A distinct N-terminal module within the fcr-1 ectodomain in conjunction with the fcr-1 transmembrane domain was required to dispose MULT-1 to degradation in lysosomes. In contrast, down-modulation of H60 required the complete fcr-1 ectodomain, implying independent modes of fcr-1 interaction with the NKG2D ligands. The results establish a novel viral strategy for down-modulating NK cell responses and highlight the impressive diversity of Fc receptor functions
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