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Extracellular DNA (eDNA) is a ubiquitous biological compound in aquatic sediment and soil. Previous studies suggested that eDNA plays an important role in biogeochemical element cycling, horizontal gene transfer and stabilization of biofilm structures. Previous methods for eDNA extraction were either not suitable for oligotrophic sediments or only allowed quantification but no genetic analyses. Our procedure is based on cell detachment and eDNA liberation from sediment particles by sequential washing with an alkaline sodium phosphate buffer followed by a separation of cells and eDNA. The separated eDNA is then bound onto silica particles and purified, whereas the intracellular DNA from the separated cells is extracted using a commercial kit. The method provides extra- and intracellular DNA of high purity that is suitable for downstream applications like PCR. Extracellular DNA was extracted from organic-rich shallow sediment of the Baltic Sea, glacially influenced sediment of the Barents Sea and from the oligotrophic South Pacific Gyre. The eDNA concentration in these samples varied from 23 to 626 ng g(-1) wet weight sediment. A number of experiments were performed to verify each processing step. Although extraction efficiency is higher than other published methods, it is not fully quantitative. (C) 2014 Elsevier B.V. All rights reserved.
An efficient, reliable and low-cost procedure to determine the silicon content in plant material is presented which allows to monitor the agricultural aspects like growth and yield. The presented procedure consists of a hydrochloric acid pre-treatment and a subsequent thermal oxidation. The method is compared to other processes like dissolution in hydrofluoric acid combined with ICP OES, energy-dispersive X-ray fluorescence spectroscopy (EDXRF) or aqua regia treatment.
A Procedural Model for the Production of reusable and standard-compliant E-Learning Offerings
(2005)
Cost-efficient production of high-quality learning contents is an important success factor for a sustainable and economic realisation of E-Learning. This necessitates the design of sustainable production processes, which create reusable Learning Objects and require minimal resources. In such a context, this contribution introduces a practical and business-process oriented Procedural Model for the Production of reusable and standard-compliant E-Learning Offerings. It has been developed and applied in a project that produces learning contents for a Master program of an international virtual university. After the introduction of a reengineering method, a special analysis instrument for E-Learning has been designed to analyse the existing production processes and to improve them in terms of efficiency, costs, standard- compliance, and process automation. The method introduced is hence not focussing on individual technical solutions but on the efficiency of the whole E-Learning production and value chain. It gives an orientation for establishing and maintaining sustainable and competitive E-Learning production processes with appropriate effort.
Extreme weather events are likely to occur more often under climate change and the resulting effects on ecosystems could lead to a further acceleration of climate change. But not all extreme weather events lead to extreme ecosystem response. Here, we focus on hazardous ecosystem behaviour and identify coinciding weather conditions. We use a simple probabilistic risk assessment based on time series of ecosystem behaviour and climate conditions. Given the risk assessment terminology, vulnerability and risk for the previously defined hazard are estimated on the basis of observed hazardous ecosystem behaviour.
We apply this approach to extreme responses of terrestrial ecosystems to drought, defining the hazard as a negative net biome productivity over a 12-month period. We show an application for two selected sites using data for 1981-2010 and then apply the method to the pan-European scale for the same period, based on numerical modelling results (LPJmL for ecosystem behaviour; ERA-Interim data for climate).
Our site-specific results demonstrate the applicability of the proposed method, using the SPEI to describe the climate condition. The site in Spain provides an example of vulnerability to drought because the expected value of the SPEI is 0.4 lower for hazardous than for non-hazardous ecosystem behaviour. In northern Germany, on the contrary, the site is not vulnerable to drought because the SPEI expectation values imply wetter conditions in the hazard case than in the non-hazard case.
At the pan-European scale, ecosystem vulnerability to drought is calculated in the Mediterranean and temperate region, whereas Scandinavian ecosystems are vulnerable under conditions without water shortages. These first model- based applications indicate the conceptual advantages of the proposed method by focusing on the identification of critical weather conditions for which we observe hazardous ecosystem behaviour in the analysed data set. Application of the method to empirical time series and to future climate would be important next steps to test the approach.
Residential assets, comprising buildings and household contents, are a major source of direct flood losses. Existing damage models are mostly deterministic and limited to particular countries or flood types. Here, we compile building-level losses from Germany, Italy and the Netherlands covering a wide range of fluvial and pluvial flood events. Utilizing a Bayesian network (BN) for continuous variables, we find that relative losses (i.e. loss relative to exposure) to building structure and its contents could be estimated with five variables: water depth, flow velocity, event return period, building usable floor space area and regional disposable income per capita. The model's ability to predict flood losses is validated for the 11 flood events contained in the sample. Predictions for the German and Italian fluvial floods were better than for pluvial floods or the 1993 Meuse river flood. Further, a case study of a 2010 coastal flood in France is used to test the BN model's performance for a type of flood not included in the survey dataset. Overall, the BN model achieved better results than any of 10 alternative damage models for reproducing average losses for the 2010 flood. An additional case study of a 2013 fluvial flood has also shown good performance of the model. The study shows that data from many flood events can be combined to derive most important factors driving flood losses across regions and time, and that resulting damage models could be applied in an open data framework.
Hegel's many remarks that seem to imply that philosophy should proceed completely a priori pose a problem for his philosophy of nature since, on this reading, Hegel offers an a priori derivation of empirical results of natural sciences. We show how this perception can be mitigated by interpreting Hegel's remarks as broadly in line with the pre-Kantian rationalist notion of a priori and offer reasons for doing so. We show that, rather than being a peculiarity of Hegel's philosophy, the practice of demonstrating a priori the results of empirical sciences was widespread in the pre-Kantian rationalist tradition. We argue that this practice was intelligible in light of the notion of a priori that was still quite prominent during Hegel's life. This notion of a priori differs from Kant's in that, while the latter's notion concerns propositions, the former concerned only their demonstration. According to it, the same proposition could be demonstrated both a posteriori and a priori. Post-Kantian idealists likewise developed projects of demonstrating specific scientific contents a priori. We then make our discussion more concrete by examining a particular case of an a priori derivation of a natural law, namely the law of fall, by both Leibniz and Hegel.
Among theories of human language comprehension, cue-based memory retrieval has proven to be a useful framework for understanding when and how processing difficulty arises in the resolution of long-distance dependencies. Most previous work in this area has assumed that very general retrieval cues like [+subject] or [+singular] do the work of identifying (and sometimes misidentifying) a retrieval target in order to establish a dependency between words. However, recent work suggests that general, handpicked retrieval cues like these may not be enough to explain illusions of plausibility (Cunnings & Sturt, 2018), which can arise in sentences like The letter next to the porcelain plate shattered. Capturing such retrieval interference effects requires lexically specific features and retrieval cues, but handpicking the features is hard to do in a principled way and greatly increases modeler degrees of freedom. To remedy this, we use well-established word embedding methods for creating distributed lexical feature representations that encode information relevant for retrieval using distributed retrieval cue vectors. We show that the similarity between the feature and cue vectors (a measure of plausibility) predicts total reading times in Cunnings and Sturt's eye-tracking data. The features can easily be plugged into existing parsing models (including cue-based retrieval and self-organized parsing), putting very different models on more equal footing and facilitating future quantitative comparisons.
A prelude to total war?
(2018)
The conflict between Italy and Ethiopia in 1935–36 has been framed as a prelude to the Second World War and as a watershed towards ‘Total War’. One perspective has so far been neglected: the assessments of foreign military observers. This article examines American, British, German, and Austrian views on the operations and thereby also analyses the mindset of European officers at the time. The core argument emerging from these reports is that the war was perceived as a rather ‘normal’ colonial conflict. Neither the use of gas, nor the employment of aircraft against civilians was seen as a taboo or created significant outrage among the military observers. Instead, they lauded the Italians’ steady logistical efforts and employment of artillery and airpower to overcome nature and the enemy’s resistance.