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The programmable network envisioned in the 1990s within standardization and research for the Intelligent Network is currently coming into reality using IPbased Next Generation Networks (NGN) and applying Service-Oriented Architecture (SOA) principles for service creation, execution, and hosting. SOA is the foundation for both next-generation telecommunications and middleware architectures, which are rapidly converging on top of commodity transport services. Services such as triple/quadruple play, multimedia messaging, and presence are enabled by the emerging service-oriented IPMultimedia Subsystem (IMS), and allow telecommunications service providers to maintain, if not improve, their position in the marketplace. SOA becomes the de facto standard in next-generation middleware systems as the system model of choice to interconnect service consumers and providers within and between enterprises. We leverage previous research activities in overlay networking technologies along with recent advances in network abstraction, service exposure, and service creation to develop a paradigm for a service environment providing converged Internet and Telecommunications services that we call Service Broker. Such a Service Broker provides mechanisms to combine and mediate between different service paradigms from the two domains Internet/WWW and telecommunications. Furthermore, it enables the composition of services across these domains and is capable of defining and applying temporal constraints during creation and execution time. By adding network-awareness into the service fabric, such a Service Broker may also act as a next generation network-to-service element allowing the composition of crossdomain and cross-layer network and service resources. The contribution of this research is threefold: first, we analyze and classify principles and technologies from Information Technologies (IT) and telecommunications to identify and discuss issues allowing cross-domain composition in a converging service layer. Second, we discuss service composition methods allowing the creation of converged services on an abstract level; in particular, we present a formalized method for model-checking of such compositions. Finally, we propose a Service Broker architecture converging Internet and Telecom services. This environment enables cross-domain feature interaction in services through formalized obligation policies acting as constraints during service discovery, creation, and execution time.
Für die Integration und den Bedarf der hochqualifizierten Migranten auf dem Arbeitsmarkt in Deutschland gibt es viele Überlegungen, aber noch keine ausreichenden Lösungen. Dieser Artikel beschreibt eine praktische Lösung über die Umsetzung des Konzepts für die Qualifizierung der akademischen Migranten am Beispiel eines Studienprogramms in Informatik an der Universität Oldenburg.
The Antarctic plays an important role in the global climate system. On the one hand, the Antarctic Ice Sheet is the largest freshwater reservoir on Earth. On the other hand, a major proportion of the global bottom-water formation takes place in Antarctic shelf regions, forcing the global thermohaline circulation. The main goal of this dissertation is to provide new insights into the dynamics and stability of the EAIS during the Quaternary. Additionally, variations in the activity of bottom-water formation and their causes are investigated. The dissertation is a German contribution to the International Polar Year 2007/ 2008 and was funded by the ‘Deutsche Forschungsgesellschaft’ (DFG) within the scope of priority program 1158 ‘Antarctic research with comparative studies in Arctic ice regions’. During RV Polarstern expedition ANT-XXIII/9, glaciomarine sediments were recovered from the Prydz Bay-Kerguelen region. Prydz Bay is a key region for the study of East EAIS dynamics, as 16% of the EAIS are drained through the Lambert Glacier into the bay. Thereby, the glacier transports sediment into Prydz Bay which is then further distributed by calving icebergs or by current transport. The scientific approach of this dissertation is the reconstruction of past glaciomarine environments to infer on the response of the Lambert Glacier-Amery Ice Shelf system to climate shifts during the Quaternary. To characterize the depositional setting, sedimentological methods are used and statistical analyses are applied. Mineralogical and (bio)geochemical methods provide a means to reconstruct sediment provenances and to provide evidence on changes in the primary production in the surface water column. Age-depth models were constructed based on palaeomagnetic and palaeointensity measurements, diatom stratigraphy and radiocarbon dating. Sea-bed surface sediments in the investigation area show distinct variations in terms of their clay minerals and heavy-mineral assemblages. Considerable differences in the mineralogical composition of surface sediments are determined on the continental shelf. Clay minerals as well as heavy minerals provide useful parameters to differentiate between sediments which originated from erosion of crystalline rocks and sediments originating from Permo-Triassic deposits. Consequently, mineralogical parameters can be used to reconstruct the provenance of current-transported and ice-rafted material. The investigated sediment cores cover the time intervals of the last 1.4 Ma (continental slope) and the last 12.8 cal. ka BP (MacRobertson shelf). The sediment deposits were mainly influenced by glacial and oceanographic processes and further by biological activity (continental shelf), meltwater input and possibly gravitational transport. Sediments from the continental slope document two major deglacial events: the first deglaciation is associated with the mid-Pleistocene warming recognized around the Antarctic. In Prydz Bay, the Lambert Glacier-Amery Ice Shelf retreated far to the south and high biogenic productivity commenced or biogenic remains were better preserved due to increased sedimentation rates. Thereafter, stable glacial conditions continued until 400 - 500 ka BP. Calving of icebergs was restricted to the western part of the Lambert Glacier. The deeper bathymetry in this area allows for floating ice shelf even during times of decreased sea-level. Between 400 - 500 ka BP and the last interglacial (marine isotope stage 5) the glacier was more dynamic. During or shortly after the last interglacial the LAIS retreated again due to sea-level rise of 6 - 9 m. Both deglacial events correlate with a reduction in the thickness of ice masses in the Prince Charles Mountains. It indicates that a disintegration of the Amery Ice Shelf possibly led to increased drainage of ice masses from the Prydz Bay hinterland. A new end-member modelling algorithm was successfully applied on sediments from the MacRobertson shelf used to unmix the sand grain size fractions sorted by current activity and ice transport, respectively. Ice retreat on MacRobertson Shelf commenced 12.8 cal. ka BP and ended around 5.5 cal. ka BP. During the Holocene, strong fluctuations of the bottomwater activity were observed, probably related to variations of sea-ice formation in the Cape Darnley polynya. Increased activity of bottom-water flow was reconstructed at transitions from warm to cool conditions, whereas bottom-water activity receded during the mid- Holocene climate optimum. It can be concluded that the Lambert Glacier-Amery Ice Shelf system was relatively stable in terms of climate variations during the Quaternary. In contrast, bottom-water formation due to polynya activity was very sensitive to changes in atmospheric forcing and should gain more attention in future research.
The origin and evolution of granites has been widely studied because granitoid rocks constitute a major portion of the Earth ́s crust. The formation of granitic magma is, besides temperature mainly triggered by the water content of these rocks. The presence of water in magmas plays an important role due to the ability of aqueous fluids to change the chemical composition of the magma. The exsolution of aqueous fluids from melts is closely linked to a fractionation of elements between the two phases. Then, aqueous fluids migrate to shallower parts of the Earth ́s crust because of it ́s lower density compared to that of melts and adjacent rocks. This process separates fluids and melts, and furthermore, during the ascent, aqueous fluids can react with the adjacent rocks and alter their chemical signature. This is particularly impor- tant during the formation of magmatic-hydrothermal ore deposits or in the late stages of the evolution of magmatic complexes. For a deeper insight to these processes, it is essential to improve our knowledge on element behavior in such systems. In particular, trace elements are used for these studies and petrogenetic interpretations because, unlike major elements, they are not essential for the stability of the phases involved and often reflect magmatic processes with less ambiguity. However, for the majority of important trace elements, the dependence of the geochemical behavior on temperature, pressure, and in particular on the composition of the system are only incompletely or not at all experimentally studied. Former studies often fo- cus on the determination of fluid−melt partition coefficients (Df/m=cfluid/cmelt) of economically interesting elements, e.g., Mo, Sn, Cu, and there are some partitioning data available for ele- ments that are also commonly used for petrological interpretations. At present, no systematic experimental data on trace element behavior in fluid−melt systems as function of pressure, temperature, and chemical composition are available. Additionally, almost all existing data are based on the analysis of quenched phases. This results in substantial uncertainties, particularly for the quenched aqueous fluid because trace element concentrations may change upon cooling. The objective of this PhD thesis consisted in the study of fluid−melt partition coefficients between aqueous solutions and granitic melts for different trace elements (Rb, Sr, Ba, La, Y, and Yb) as a function of temperature, pressure, salinity of the fluid, composition of the melt, and experimental and analytical approach. The latter included the refinement of an existing method to measure trace element concentrations in fluids equilibrated with silicate melts di- rectly at elevated pressures and temperatures using a hydrothermal diamond-anvil cell and synchrotron radiation X-ray fluorescence microanalysis. The application of this in-situ method enables to avoid the main source of error in data from quench experiments, i.e., trace element concentration in the fluid. A comparison of the in-situ results to data of conventional quench experiments allows a critical evaluation of quench data from this study and literature data. In detail, starting materials consisted of a suite of trace element doped haplogranitic glasses with ASI varying between 0.8 and 1.4 and H2O or a chloridic solution with m NaCl/KCl=1 and different salinities (1.16 to 3.56 m (NaCl+KCl)). Experiments were performed at 750 to 950◦C and 0.2 or 0.5 GPa using conventional quench devices (externally and internally heated pressure vessels) with different quench rates, and at 750◦C and 0.2 to 1.4 GPa with in-situ analysis of the trace element concentration in the fluids. The fluid−melt partitioning data of all studied trace elements show 1. a preference for the melt (Df/m < 1) at all studied conditions, 2. one to two orders of magnitude higher Df/m using chloridic solutions compared to experiments with H2O, 3. a clear dependence on the melt composition for fluid−melt partitioning of Sr, Ba, La, Y, and Yb in experiments using chloridic solutions, 4. quench rate−related differences of fluid−melt partition coefficients of Rb and Sr, and 5. distinctly higher fluid−melt partitioning data obtained from in-situ experiments than from comparable quench runs, particularly in the case of H2O as starting solution. The data point to a preference of all studied trace elements for the melt even at fairly high salinities, which contrasts with other experimental studies, but is supported by data from studies of natural co-genetically trapped fluid and melt inclusions. The in-situ measurements of trace element concentrations in the fluid verify that aqueous fluids will change their composition upon cooling, which is in particular important for Cl free systems. The distinct differences of the in-situ results to quench data of this study as well as to data from the literature signify the im- portance of a careful fluid sampling and analysis. Therefore, the direct measurement of trace element contents in fluids equilibrated with silicate melts at elevated PT conditions represents an important development to obtain more reliable fluid−melt partition coefficients. For further improvement, both the aqueous fluid and the silicate melt need to be analyzed in-situ because partitioning data that are based on the direct measurement of the trace element content in the fluid and analysis of a quenched melt are still not completely free of quench effects. At present, all available data on element complexation in aqueous fluids in equilibrium with silicate melts at high PT are indirectly derived from partitioning data, which involves in these experiments assumptions on the species present in the fluid. However, the activities of chemical components in these partitioning experiments are not well constrained, which is required for the definition of exchange equilibria between melt and fluid species. For example, the melt-dependent variation of partition coefficient observed for Sr imply that this element can not only be complexed by Cl− as suggested previously. The data indicate a more complicated complexation of Sr in the aqueous fluid. To verify this hypothesis, the in-situ setup was also used to determine strontium complexation in fluids equilibrated with silicate melts at desired PT conditions by the application of X-ray absorption near edge structure (XANES) spectroscopy. First results show a strong effect of both fluid and melt composition on the resulting XANES spectra, which indicates different complexation environments for Sr.
Gegenstand der Studie ist die Evaluation eines kommunalen Sportprojekts. Die Forschungsarbeit entstand aus der wachsenden Erkenntnis heraus, dass es nicht mehr nur um die Entwicklung und Durchführung kommunaler oder sozialer Projekte geht, sondern zunehmend darauf ankommt, die Projektarbeit zu evaluieren, um ihren Einfluss auf die kommunale, soziale und personale Entwicklung zu prüfen und in der Folge die Implementierung zu optimieren. Die unterschiedlichen Schritte in der Definition des theoretischen Rahmens, der Datenanalyse sowie der Erarbeitung der evaluativen Empfehlungen wurden unternommen mit dem Anspruch auf Modellcharakter, um für zukünftige Evaluationsvorhaben entsprechende Standards zu setzen. Die Grundidee des kommunalen Sportprojekts „Straßenfußball für Toleranz“ ist innovativ: Mädchen und Jungen erobern durch gemeinsames Fußballspielen den öffentlichen Raum. Sie spielen ohne Schiedsrichter und nach speziellen Regeln. Das Projekt richtet sich ausdrücklich an sozial benachteiligte Jugendliche und bezieht gleichermaßen Jungen wie Mädchen ein.
Der Beitrag erinnert an das wechselvolle Leben des Friedensnobelpreisträgers Henry Dunant, sucht nach biografischen Wurzeln seines von Menschlichkeit und Würde getragenen Verhaltens und macht auf seine Leistungen aufmerksam. Er will aber auch die Frage nach der Bedeutung des humanitären Völkerrechts im Verhältnis von Krieg und Frieden nicht außer Acht lassen.
Aus dem Inhalt: - Extraterritoriale Staatenpflichten und internationale Friedensmissionen - Der Einfluss der Allgemeinen Erklärung der Menschenrechte auf die Aufnahme des Grundrechts auf Asyl in das Grundgesetz - Die OECD-Leitsätze für multinationale Unternehmen: Funktionsweise und Umsetzung - Folterprävention in Deutschland – Die neue Bundesstelle zur Verhütung von Folter
Deductive databases need general formulas in rule bodies, not only conjuctions of literals. This is well known since the work of Lloyd and Topor about extended logic programming. Of course, formulas must be restricted in such a way that they can be effectively evaluated in finite time, and produce only a finite number of new tuples (in each iteration of the TP-operator: the fixpoint can still be infinite). It is also necessary to respect binding restrictions of built-in predicates: many of these predicates can be executed only when certain arguments are ground. Whereas for standard logic programming rules, questions of safety, allowedness, and range-restriction are relatively easy and well understood, the situation for general formulas is a bit more complicated. We give a syntactic analysis of formulas that guarantees the necessary properties.
Die automatische Informationsextraktion (IE) aus unstrukturierten Texten ermöglicht völlig neue Wege, auf relevante Informationen zuzugreifen und deren Inhalte zu analysieren, die weit über bisherige Verfahren zur Stichwort-basierten Dokumentsuche hinausgehen. Die Entwicklung von Programmen zur Extraktion von maschinenlesbaren Daten aus Texten erfordert jedoch nach wie vor die Entwicklung von domänenspezifischen Extraktionsprogrammen. Insbesondere im Bereich der Enterprise Search (der Informationssuche im Unternehmensumfeld), in dem eine große Menge von heterogenen Dokumenttypen existiert, ist es oft notwendig ad-hoc Programm-module zur Extraktion von geschäftsrelevanten Entitäten zu entwickeln, die mit generischen Modulen in monolithischen IE-Systemen kombiniert werden. Dieser Umstand ist insbesondere kritisch, da potentiell für jeden einzelnen Anwendungsfall ein von Grund auf neues IE-System entwickelt werden muss. Die vorliegende Dissertation untersucht die effiziente Entwicklung und Ausführung von IE-Systemen im Kontext der Enterprise Search und effektive Methoden zur Ausnutzung bekannter strukturierter Daten im Unternehmenskontext für die Extraktion und Identifikation von geschäftsrelevanten Entitäten in Doku-menten. Grundlage der Arbeit ist eine neuartige Plattform zur Komposition von IE-Systemen auf Basis der Beschreibung des Datenflusses zwischen generischen und anwendungsspezifischen IE-Modulen. Die Plattform unterstützt insbesondere die Entwicklung und Wiederverwendung von generischen IE-Modulen und zeichnet sich durch eine höhere Flexibilität und Ausdrucksmächtigkeit im Vergleich zu vorherigen Methoden aus. Ein in der Dissertation entwickeltes Verfahren zur Dokumentverarbeitung interpretiert den Daten-austausch zwischen IE-Modulen als Datenströme und ermöglicht damit eine weitgehende Parallelisierung von einzelnen Modulen. Die autonome Ausführung der Module führt zu einer wesentlichen Beschleu-nigung der Verarbeitung von Einzeldokumenten und verbesserten Antwortzeiten, z. B. für Extraktions-dienste. Bisherige Ansätze untersuchen lediglich die Steigerung des durchschnittlichen Dokumenten-durchsatzes durch verteilte Ausführung von Instanzen eines IE-Systems. Die Informationsextraktion im Kontext der Enterprise Search unterscheidet sich z. B. von der Extraktion aus dem World Wide Web dadurch, dass in der Regel strukturierte Referenzdaten z. B. in Form von Unternehmensdatenbanken oder Terminologien zur Verfügung stehen, die oft auch die Beziehungen von Entitäten beschreiben. Entitäten im Unternehmensumfeld haben weiterhin bestimmte Charakteristiken: Eine Klasse von relevanten Entitäten folgt bestimmten Bildungsvorschriften, die nicht immer bekannt sind, auf die aber mit Hilfe von bekannten Beispielentitäten geschlossen werden kann, so dass unbekannte Entitäten extrahiert werden können. Die Bezeichner der anderen Klasse von Entitäten haben eher umschreibenden Charakter. Die korrespondierenden Umschreibungen in Texten können variieren, wodurch eine Identifikation derartiger Entitäten oft erschwert wird. Zur effizienteren Entwicklung von IE-Systemen wird in der Dissertation ein Verfahren untersucht, das alleine anhand von Beispielentitäten effektive Reguläre Ausdrücke zur Extraktion von unbekannten Entitäten erlernt und damit den manuellen Aufwand in derartigen Anwendungsfällen minimiert. Verschiedene Generalisierungs- und Spezialisierungsheuristiken erkennen Muster auf verschiedenen Abstraktionsebenen und schaffen dadurch einen Ausgleich zwischen Genauigkeit und Vollständigkeit bei der Extraktion. Bekannte Regellernverfahren im Bereich der Informationsextraktion unterstützen die beschriebenen Problemstellungen nicht, sondern benötigen einen (annotierten) Dokumentenkorpus. Eine Methode zur Identifikation von Entitäten, die durch Graph-strukturierte Referenzdaten vordefiniert sind, wird als dritter Schwerpunkt untersucht. Es werden Verfahren konzipiert, welche über einen exakten Zeichenkettenvergleich zwischen Text und Referenzdatensatz hinausgehen und Teilübereinstimmungen und Beziehungen zwischen Entitäten zur Identifikation und Disambiguierung heranziehen. Das in der Arbeit vorgestellte Verfahren ist bisherigen Ansätzen hinsichtlich der Genauigkeit und Vollständigkeit bei der Identifikation überlegen.
Background
Micrometer resolution placement and immobilization of probe molecules is an important step in the preparation of biochips and a wide range of lab-on-chip systems. Most known methods for such a deposition of several different substances are costly and only suitable for a limited number of probes. In this article we present a flexible procedure for simultaneous spatially controlled immobilization of functional biomolecules by molecular ink lithography.
Results
For the bottom-up fabrication of surface bound nanostructures a universal method is presented that allows the immobilization of different types of biomolecules with micrometer resolution. A supporting surface is biotinylated and streptavidin molecules are deposited with an AFM (atomic force microscope) tip at distinct positions. Subsequent incubation with a biotinylated molecule species leads to binding only at these positions. After washing streptavidin is deposited a second time with the same AFM tip and then a second biotinylated molecule species is coupled by incubation. This procedure can be repeated several times. Here we show how to immobilize different types of biomolecules in an arbitrary arrangement whereas most common methods can deposit only one type of molecules. The presented method works on transparent as well as on opaque substrates. The spatial resolution is better than 400 nm and is limited only by the AFM's positional accuracy after repeated z-cycles since all steps are performed in situ without moving the supporting surface. The principle is demonstrated by hybridization to different immobilized DNA oligomers and was validated by fluorescence microscopy.
Conclusions
The immobilization of different types of biomolecules in high-density microarrays is a challenging task for biotechnology. The method presented here not only allows for the deposition of DNA at submicrometer resolution but also for proteins and other molecules of biological relevance that can be coupled to biotin.
Und der Zukunft abgewandt
(2010)
Seit dem Ende der DDR, das den Zusammenbruch des Ostblocks und damit die Beendigung des »Kalten Kriegs« einleitete, wird verstärkt versucht, das Wesen dieses Staates zu definieren und damit seine Folgen auf wirtschaftlicher, sozialer, psychologischer und bildungspolitischer Ebene zu verstehen und einzuordnen. Alexandra Budke analysiert in diesem Band das Schulfach Geographie, das neben der Staatsbürgerkunde und der Geschichte ein zentrales Fach war und in dem die in den Lehrplänen definierte »staatsbürgerliche, weltanschauliche oder ideologische Erziehung« auf der Grundlage des Marxismus-Leninismus stattfinden sollte. Sie klärt, inwiefern Geographieunterricht in der DDR genutzt wurde, um geopolitische Interessen des Staates zu kommunizieren und zu verbreiten. Damit lässt sich durch die detaillierte Analyse des Fachunterrichts auch die Frage beantworten, ob SchülerInnen im Unterricht politisch manipuliert wurden und welche Handlungsmöglichkeiten die zentralen Akteure des Unterrichts, die LehrerInnen und die SchülerInnen, im Rahmen der durch die Bildungspolitik gesetzten curricularen Vorgaben wahrgenommen haben.
This paper is a critical examination of the relationship between reality and simulation. After a brief theoretical introduction, it unfolds its argument on an empirical level, using a thick game playing description of GRAND THEFT AUTO IV. This in-game experience serves as material for the subsequent analysis, in the course of which defining characteristics of computer game playing are formulated. Finally, on the basis of this analysis, the paper postulates the hypothesis that playing computer games like GTA IV promotes competency in deconstructing simulations and implements a cyclic logic of recreation.
Because software development is increasingly expensive and timeconsuming, software reuse gains importance. Aspect-oriented software development modularizes crosscutting concerns which enables their systematic reuse. Literature provides a number of AOP patterns and best practices for developing reusable aspects based on compelling examples for concerns like tracing, transactions and persistence. However, such best practices are lacking for systematically reusing invasive aspects. In this paper, we present the ‘callback mismatch problem’. This problem arises in the context of abstraction mismatch, in which the aspect is required to issue a callback to the base application. As a consequence, the composition of invasive aspects is cumbersome to implement, difficult to maintain and impossible to reuse. We motivate this problem in a real-world example, show that it persists in the current state-of-the-art, and outline the need for advanced aspectual composition mechanisms to deal with this.
Based on technological advances made within the past decades, ground-penetrating radar (GPR) has become a well-established, non-destructive subsurface imaging technique. Catalyzed by recent demands for high-resolution, near-surface imaging (e.g., the detection of unexploded ordnances and subsurface utilities, or hydrological investigations), the quality of today's GPR-based, near-surface images has significantly matured. At the same time, the analysis of oil and gas related reflection seismic data sets has experienced significant advances. Considering the sensitivity of attribute analysis with respect to data positioning in general, and multi-trace attributes in particular, trace positioning accuracy is of major importance for the success of attribute-based analysis flows. Therefore, to study the feasibility of GPR-based attribute analyses, I first developed and evaluated a real-time GPR surveying setup based on a modern tracking total station (TTS). The combination of current GPR systems capability of fusing global positioning system (GPS) and geophysical data in real-time, the ability of modern TTS systems to generate a GPS-like positional output and wireless data transmission using radio modems results in a flexible and robust surveying setup. To elaborate the feasibility of this setup, I studied the major limitations of such an approach: system cross-talk and data delays known as latencies. Experimental studies have shown that when a minimal distance of ~5 m between the GPR and the TTS system is considered, the signal-to-noise ratio of the acquired GPR data using radio communication equals the one without radio communication. To address the limitations imposed by system latencies, inherent to all real-time data fusion approaches, I developed a novel correction (calibration) strategy to assess the gross system latency and to correct for it. This resulted in the centimeter trace accuracy required by high-frequency and/or three-dimensional (3D) GPR surveys. Having introduced this flexible high-precision surveying setup, I successfully demonstrated the application of attribute-based processing to GPR specific problems, which may differ significantly from the geological ones typically addressed by the oil and gas industry using seismic data. In this thesis, I concentrated on archaeological and subsurface utility problems, as they represent typical near-surface geophysical targets. Enhancing 3D archaeological GPR data sets using a dip-steered filtering approach, followed by calculation of coherency and similarity, allowed me to conduct subsurface interpretations far beyond those obtained by classical time-slice analyses. I could show that the incorporation of additional data sets (magnetic and topographic) and attributes derived from these data sets can further improve the interpretation. In a case study, such an approach revealed the complementary nature of the individual data sets and, for example, allowed conclusions about the source location of magnetic anomalies by concurrently analyzing GPR time/depth slices to be made. In addition to archaeological targets, subsurface utility detection and characterization is a steadily growing field of application for GPR. I developed a novel attribute called depolarization. Incorporation of geometrical and physical feature characteristics into the depolarization attribute allowed me to display the observed polarization phenomena efficiently. Geometrical enhancement makes use of an improved symmetry extraction algorithm based on Laplacian high-boosting, followed by a phase-based symmetry calculation using a two-dimensional (2D) log-Gabor filterbank decomposition of the data volume. To extract the physical information from the dual-component data set, I employed a sliding-window principle component analysis. The combination of the geometrically derived feature angle and the physically derived polarization angle allowed me to enhance the polarization characteristics of subsurface features. Ground-truth information obtained by excavations confirmed this interpretation. In the future, inclusion of cross-polarized antennae configurations into the processing scheme may further improve the quality of the depolarization attribute. In addition to polarization phenomena, the time-dependent frequency evolution of GPR signals might hold further information on the subsurface architecture and/or material properties. High-resolution, sparsity promoting decomposition approaches have recently had a significant impact on the image and signal processing community. In this thesis, I introduced a modified tree-based matching pursuit approach. Based on different synthetic examples, I showed that the modified tree-based pursuit approach clearly outperforms other commonly used time-frequency decomposition approaches with respect to both time and frequency resolutions. Apart from the investigation of tuning effects in GPR data, I also demonstrated the potential of high-resolution sparse decompositions for advanced data processing. Frequency modulation of individual atoms themselves allows to efficiently correct frequency attenuation effects and improve resolution based on shifting the average frequency level. GPR-based attribute analysis is still in its infancy. Considering the growing widespread realization of 3D GPR studies there will certainly be an increasing demand towards improved subsurface interpretations in the future. Similar to the assessment of quantitative reservoir properties through the combination of 3D seismic attribute volumes with sparse well-log information, parameter estimation in a combined manner represents another step in emphasizing the potential of attribute-driven GPR data analyses.
In this paper we consider a simple syntactic extension of Answer Set Programming (ASP) for dealing with (nested) existential quantifiers and double negation in the rule bodies, in a close way to the recent proposal RASPL-1. The semantics for this extension just resorts to Equilibrium Logic (or, equivalently, to the General Theory of Stable Models), which provides a logic-programming interpretation for any arbitrary theory in the syntax of Predicate Calculus. We present a translation of this syntactic class into standard logic programs with variables (either disjunctive or normal, depending on the input rule heads), as those allowed by current ASP solvers. The translation relies on the introduction of auxiliary predicates and the main result shows that it preserves strong equivalence modulo the original signature.
How much is too much?
(2010)
Although dietary nutrient intake is often adequate, nutritional supplement use is common among elite athletes. However, high-dose supplements or the use of multiple supplements may exceed the recommended daily allowance (RDA) of particular nutrients or even result in a daily intake above tolerable upper limits (UL). The present case report presents nutritional intake data and supplement use of a highly trained male swimmer competing at international level. Habitual energy and micronutrient intake were analysed by 3 d dietary reports. Supplement use and dosage were assessed, and total amount of nutrient supply was calculated. Micronutrient intake was evaluated based on RDA and UL as presented by the European Scientific Committee on Food, and maximum permitted levels in supplements (MPL) are given. The athlete’s diet provided adequate micronutrient content well above RDA except for vitamin D. Simultaneous use of ten different supplements was reported, resulting in excess intake above tolerable UL for folate, vitamin E and Zn. Additionally, daily supplement dosage was considerably above MPL for nine micronutrients consumed as artificial products. Risks and possible side effects of exceeding UL by the athlete are discussed. Athletes with high energy intake may be at risk of exceeding UL of particular nutrients if multiple supplements are added. Therefore, dietary counselling of athletes should include assessment of habitual diet and nutritional supplement intake. Educating athletes to balance their diets instead of taking supplements might be prudent to prevent health risks
that may occur with long-term excess nutrient intake.
Communication, simulation, interactive narrative and ubiquitous computing are widely accepted as perspectives in humancomputer interaction. This paper proposes play as another possible perspective. Everyday uses of the computer increasingly show signs of similarity to play. This is not discussed with regard to the so-called media society, the playful society, the growing cultural acceptance of the computer, the spread of computer games or a new version of Windows, but in view of the playful character of interaction with the computer that has always been part of it. The exploratory learning process involved with new software and the creative tasks that are often undertaken when using the computer may support this argument. Together with its high level of interactivity, these observations point to a sense of security, autonomy and freedom of the user that produce play and are, in turn, produced by play. This notion of play refers not to the playing of computer games, but to an implicit, abstract (or symbolic) process based on a certain attitude, the play spirit. This attitude is discussed regarding everyday computer use and related to the other mentioned perspectives.
The genome can be considered the blueprint for an organism. Composed of DNA, it harbours all organism-specific instructions for the synthesis of all structural components and their associated functions. The role of carriers of actual molecular structure and functions was believed to be exclusively assumed by proteins encoded in particular segments of the genome, the genes. In the process of converting the information stored genes into functional proteins, RNA – a third major molecule class – was discovered early on to act a messenger by copying the genomic information and relaying it to the protein-synthesizing machinery. Furthermore, RNA molecules were identified to assist in the assembly of amino acids into native proteins. For a long time, these - rather passive - roles were thought to be the sole purpose of RNA. However, in recent years, new discoveries have led to a radical revision of this view. First, RNA molecules with catalytic functions - thought to be the exclusive domain of proteins - were discovered. Then, scientists realized that much more of the genomic sequence is transcribed into RNA molecules than there are proteins in cells begging the question what the function of all these molecules are. Furthermore, very short and altogether new types of RNA molecules seemingly playing a critical role in orchestrating cellular processes were discovered. Thus, RNA has become a central research topic in molecular biology, even to the extent that some researcher dub cells as “RNA machines”. This thesis aims to contribute towards our understanding of RNA-related phenomena by applying Bioinformatics means. First, we performed a genome-wide screen to identify sites at which the chemical composition of DNA (the genotype) critically influences phenotypic traits (the phenotype) of the model plant Arabidopsis thaliana. Whole genome hybridisation arrays were used and an informatics strategy developed, to identify polymorphic sites from hybridisation to genomic DNA. Following this approach, not only were genotype-phenotype associations discovered across the entire Arabidopsis genome, but also regions not currently known to encode proteins, thus representing candidate sites for novel RNA functional molecules. By statistically associating them with phenotypic traits, clues as to their particular functions were obtained. Furthermore, these candidate regions were subjected to a novel RNA-function classification prediction method developed as part of this thesis. While determining the chemical structure (the sequence) of candidate RNA molecules is relatively straightforward, the elucidation of its structure-function relationship is much more challenging. Towards this end, we devised and implemented a novel algorithmic approach to predict the structural and, thereby, functional class of RNA molecules. In this algorithm, the concept of treating RNA molecule structures as graphs was introduced. We demonstrate that this abstraction of the actual structure leads to meaningful results that may greatly assist in the characterization of novel RNA molecules. Furthermore, by using graph-theoretic properties as descriptors of structure, we indentified particular structural features of RNA molecules that may determine their function, thus providing new insights into the structure-function relationships of RNA. The method (termed Grapple) has been made available to the scientific community as a web-based service. RNA has taken centre stage in molecular biology research and novel discoveries can be expected to further solidify the central role of RNA in the origin and support of life on earth. As illustrated by this thesis, Bioinformatics methods will continue to play an essential role in these discoveries.
This thesis is concerned with the development of numerical methods using finite difference techniques for the discretization of initial value problems (IVPs) and initial boundary value problems (IBVPs) of certain hyperbolic systems which are first order in time and second order in space. This type of system appears in some formulations of Einstein equations, such as ADM, BSSN, NOR, and the generalized harmonic formulation. For IVP, the stability method proposed in [14] is extended from second and fourth order centered schemes, to 2n-order accuracy, including also the case when some first order derivatives are approximated with off-centered finite difference operators (FDO) and dissipation is added to the right-hand sides of the equations. For the model problem of the wave equation, special attention is paid to the analysis of Courant limits and numerical speeds. Although off-centered FDOs have larger truncation errors than centered FDOs, it is shown that in certain situations, off-centering by just one point can be beneficial for the overall accuracy of the numerical scheme. The wave equation is also analyzed in respect to its initial boundary value problem. All three types of boundaries - outflow, inflow and completely inflow that can appear in this case, are investigated. Using the ghost-point method, 2n-accurate (n = 1, 4) numerical prescriptions are prescribed for each type of boundary. The inflow boundary is also approached using the SAT-SBP method. In the end of the thesis, a 1-D variant of BSSN formulation is derived and some of its IBVPs are considered. The boundary procedures, based on the ghost-point method, are intended to preserve the interior 2n-accuracy. Numerical tests show that this is the case if sufficient dissipation is added to the rhs of the equations.
Inhalt: Gründe für das Entstehen der Parteienfinanzierung aus dem Staatshaushalt ; Argumente für und gegen die Haushaltsfinanzierung politischer Parteien ; Finanzierung politischer Parteien in Polen nach 1989 ; Die Diskussion über das System der Finanzierung politischer Parteien in Polen ; Zusammenfassung ; Literatur
The issue of determining the time, when the Judaic communities have settled on Romanian land, is one of the most interesting and most delicate details that can be mentioned when talking about this ethnic group. The presence of the first Jewish communities in ancient times on this land was a “taboo” subject during many historical periods until 1989, but even after this year, studies oriented in this direction were more than sketchy. The article does not only bring a surplus of information in this domain, but manages to concentrate – almost didactically – the information and the archaeological proofs known and reknown to the present time. There are depicted material evidences as well as linguistic ones, toponymical and even religious. Also, the author tries to draw a parallel between some layouts of the Dacian state and Dacia Felix, conquered by the Romans, and the presence of some Judaic communities, not very numerous, made out of Judaic population who came together with the Roman conqueror.
Temporal gravimeter observations, used in geodesy and geophysics to study variation of the Earth’s gravity field, are influenced by local water storage changes (WSC) and – from this perspective – add noise to the gravimeter signal records. At the same time, the part of the gravity signal caused by WSC may provide substantial information for hydrologists. Water storages are the fundamental state variable of hydrological systems, but comprehensive data on total WSC are practically inaccessible and their quantification is associated with a high level of uncertainty at the field scale. This study investigates the relationship between temporal gravity measurements and WSC in order to reduce the hydrological interfering signal from temporal gravity measurements and to explore the value of temporal gravity measurements for hydrology for the superconducting gravimeter (SG) of the Geodetic Observatory Wettzell, Germany. A 4D forward model with a spatially nested discretization domain was developed to simulate and calculate the local hydrological effect on the temporal gravity observations. An intensive measurement system was installed at the Geodetic Observatory Wettzell and WSC were measured in all relevant storage components, namely groundwater, saprolite, soil, top soil and snow storage. The monitoring system comprised also a suction-controlled, weighable, monolith-filled lysimeter, allowing an all time first comparison of a lysimeter and a gravimeter. Lysimeter data were used to estimate WSC at the field scale in combination with complementary observations and a hydrological 1D model. Total local WSC were derived, uncertainties were assessed and the hydrological gravity response was calculated from the WSC. A simple conceptual hydrological model was calibrated and evaluated against records of a superconducting gravimeter, soil moisture and groundwater time series. The model was evaluated by a split sample test and validated against independently estimated WSC from the lysimeter-based approach. A simulation of the hydrological gravity effect showed that WSC of one meter height along the topography caused a gravity response of 52 µGal, whereas, generally in geodesy, on flat terrain, the same water mass variation causes a gravity change of only 42 µGal (Bouguer approximation). The radius of influence of local water storage variations can be limited to 1000 m and 50 % to 80 % of the local hydro¬logical gravity signal is generated within a radius of 50 m around the gravimeter. At the Geodetic Observatory Wettzell, WSC in the snow pack, top soil, unsaturated saprolite and fractured aquifer are all important terms of the local water budget. With the exception of snow, all storage components have gravity responses of the same order of magnitude and are therefore relevant for gravity observations. The comparison of the total hydrological gravity response to the gravity residuals obtained from the SG, showed similarities in both short-term and seasonal dynamics. However, the results demonstrated the limitations of estimating total local WSC using hydrological point measurements. The results of the lysimeter-based approach showed that gravity residuals are caused to a larger extent by local WSC than previously estimated. A comparison of the results with other methods used in the past to correct temporal gravity observations for the local hydrological influence showed that the lysimeter measurements improved the independent estimation of WSC significantly and thus provided a better way of estimating the local hydrological gravity effect. In the context of hydrological noise reduction, at sites where temporal gravity observations are used for geophysical studies beyond local hydrology, the installation of a lysimeter in combination with complementary hydrological measurements is recommended. From the hydrological view point, using gravimeter data as a calibration constraint improved the model results in comparison to hydrological point measurements. Thanks to their capacity to integrate over different storage components and a larger area, gravimeters provide generalized information on total WSC at the field scale. Due to their integrative nature, gravity data must be interpreted with great care in hydrological studies. However, gravimeters can serve as a novel measurement instrument for hydrology and the application of gravimeters especially designed to study open research questions in hydrology is recommended.
Es geht nicht um "Versagen"!
(2010)
Die sich zunächst um Griechenland rankende Krise wurde zu einer europäischen, die den Euro bedroht. Allenthalben wird die Frage gestellt: Wer ist schuld? In deutschen Groß-Medien wird auf das Zögern der derzeitigen Bundesregierung verwiesen. Der Euro rutschte in die Gefahrenzone. Aber ist der Verweis auf falsche Politik die Antwort auf die Frage nach dem erneuten Aufbrechen der Finanzkrise?
rezensiertes Werk: Grossman, David: Eine Frau flieht vor einer Nachricht. - München : Hanser, 2009. - 728 S. ISBN 978-3-446-23397-3
In reading, word frequency is commonly regarded as the major bottom-up determinant for the speed of lexical access. Moreover, language processing depends on top-down information, such as the predictability of a word from a previous context. Yet, however, the exact role of top-down predictions in visual word recognition is poorly understood: They may rapidly affect lexical processes, or alternatively, influence only late post-lexical stages. To add evidence about the nature of top-down processes and their relation to bottom-up information in the timeline of word recognition, we examined influences of frequency and predictability on event-related potentials (ERPs) in several sentence reading studies. The results were related to eye movements from natural reading as well as to models of word recognition. As a first and major finding, interactions of frequency and predictability on ERP amplitudes consistently revealed top-down influences on lexical levels of word processing (Chapters 2 and 4). Second, frequency and predictability mediated relations between N400 amplitudes and fixation durations, pointing to their sensitivity to a common stage of word recognition; further, larger N400 amplitudes entailed longer fixation durations on the next word, a result providing evidence for ongoing processing beyond a fixation (Chapter 3). Third, influences of presentation rate on ERP frequency and predictability effects demonstrated that the time available for word processing critically co-determines the course of bottom-up and top-down influences (Chapter 4). Fourth, at a near-normal reading speed, an early predictability effect suggested the rapid comparison of top-down hypotheses with the actual visual input (Chapter 5). The present results are compatible with interactive models of word recognition assuming that early lexical processes depend on the concerted impact of bottom-up and top-down information. We offered a framework that reconciles the findings on a timeline of word recognition taking into account influences of frequency, predictability, and presentation rate (Chapter 4).
Geographical turn
(2010)
Uno de los misterios más persistentes en América ha sido dilucidar el origen de los pueblos vernáculos y de sus edificios. Resolver ese misterio ha sido objetivo de numerosos viajeros. Entre 1832 y 1836, siguiendo la estela de viajeros como Alejandro de Humboldt, un supuesto barón checo, Frédéric de Waldeck, consigue vender al gobierno mexicano una empresa exploratoria por las ruinas mayas de Palenque y Uxmal. De esta expedición deja testimonio en numerosos diarios que permanecen inéditos hasta la fecha, y en el libro Voyage pittoresque et archéologique dans la Province d’ Yucatán (1838). En estos escritos ensaya algunas explicaciones sobre el origen de los mayas y, en sus disquisiciones y supuestos, hace continuas referencias al trabajo de Humboldt. En un artículo previo vimos cómo Waldeck asimila el origen de los mayas a uno de los grandes misterios bíblicos de raíz histórica como es el de las tribus perdidas de Israel. En este trabajo presentamos su segunda gran hipótesis: aquella que vincula a Yucatán con la India a través de un modo de interpretar y representar la realidad americana que tiene en el orientalismo europeo su episteme definitiva.
Recent large earthquakes put in evidence the need of improving and developing robust and rapid procedures to properly calculate the magnitude of an earthquake in a short time after its occurrence. The most famous example is the 26 December 2004 Sumatra earthquake, when the limitations of the standard procedures adopted at that time by many agencies failed to provide accurate magnitude estimates of this exceptional event in time to launch early enough warnings and appropriate response. Being related to the radiated seismic energy ES, the energy magnitude ME is a good estimator of the high frequency content radiated by the source which goes into the seismic waves. However, a procedure to rapidly determine ME (that is to say, within 15 minutes after the earthquake occurrence) was required. Here it is presented a procedure able to provide in a rapid way the energy magnitude ME for shallow earthquakes by analyzing teleseismic P‑waves in the distance range 20-98. To account for the energy loss experienced by the seismic waves from the source to the receivers, spectral amplitude decay functions obtained from numerical simulations of Greens functions based on the average global model AK135Q are used. The proposed method has been tested using a large global dataset (~1000 earthquakes) and the obtained rapid ME estimations have been compared to other magnitude scales from different agencies. Special emphasis is given to the comparison with the moment magnitude MW, since the latter is very popular and extensively used in common seismological practice. However, it is shown that MW alone provide only limited information about the seismic source properties, and that disaster management organizations would benefit from a combined use of MW and ME in the prompt evaluation of an earthquake’s tsunami and shaking potential. In addition, since the proposed approach for ME is intended to work without knowledge of the fault plane geometry (often available only hours after an earthquake occurrence), the suitability of this method is discussed by grouping the analyzed earthquakes according to their type of mechanism (strike-slip, normal faulting, thrust faulting, etc.). No clear trend is found from the rapid ME estimates with the different fault plane solution groups. This is not the case for the ME routinely determined by the U.S. Geological Survey, which uses specific radiation pattern corrections. Further studies are needed to verify the effect of such corrections on ME estimates. Finally, exploiting the redundancy of the information provided by the analyzed dataset, the components of variance on the single station ME estimates are investigated. The largest component of variance is due to the intra-station (record-to-record) error, although the inter-station (station-to-station) error is not negligible and is of several magnitude units for some stations. Moreover, it is shown that the intra-station component of error is not random but depends on the travel path from a source area to a given station. Consequently, empirical corrections may be used to account for the heterogeneities of the real Earth not considered in the theoretical calculations of the spectral amplitude decay functions used to correct the recorded data for the propagation effects.
Die vorliegende Zusammenstellung deutscher Menschenrechtspreise dokumentiert menschenrechtliches Engagement aus verschiedenen Perspektiven: - Erstens gibt die Sammlung einen Überblick über die von Einrichtungen und Organisationen vergebenen Menschenrechtspreise. Sie informiert über die Preise selbst und über die aktuellen Preisträger ebenso wie über die Wertvorstellungen und Ziele ihrer Stifter und deren postalische und elektronische Adressen, um bei der Suche nach möglichen Ansprechpartnern behilflich zu sein. - Zweitens vermittelt die Sammlung einen Eindruck von der Vielfalt menschenrechtlichen Handelns am Beispiel der aktuellen Preisträger und weist auf ihre herausragenden und zu würdigenden Leistungen hin. Die Zusammenstellung zeigt, dass Empathie und Empowerment möglich und dem Anliegen förderlich sind. - Drittens bekundet sie das Bedürfnis, den Einsatz für Menschenwürde und Schutz der Menschenrechte öffentlich zu ehren. Damit ist die Absicht verbunden, gesellschaftliches Interesse für diese Fragen zu wecken, die dem Ziel folgt, Menschenrechte leben zu lernen. Die überwiegende Mehrheit – das heißt 35 – der aktuell insgesamt 43 deutschen Menschenrechtspreise wurde erst in den letzten 20 Jahren eingerichtet. Das lässt auch auf den wachsenden Nachdruck im menschenrechtsverbundenen Auftreten (und Handeln) von politischen, konfessionellen, künstlerischen, sportlichen oder auch privatwirtschaftlichen Verantwortungsträgern schließen. Aus der Vielzahl der vergebenen Ehrenpreise wurden all jene Auszeichnungen in der Auflistung berücksichtigt, die entweder im Titel oder in der Beschreibung der Vergabekriterien und Begründungen auf die Begriffe der Menschenrechte und Menschenwürde Bezug nehmen. Grundlage der Daten und Einschätzungen sind in der Regel die Selbstdarstellungen der Vergabeeinrichtungen, wie sie ihren Homepages zu entnehmen waren. Die Web-Adressen – wie unter der Rubrik Kontakt jeweils angegeben – gelten als Beleg. Stichtag für den Rechercheschluss ist der 30. April 2010.
Das Erkenntnisziel der Analyse der Vermögenslage ist die Gewinnung von Informationen über das Vermögen eines Unternehmens und seine Investitionstätigkeiten. In dieser Arbeit stellt das Definitionssystem der Jahresabschlussanalyse (in der Fachliteratur auch Bilanzanalyse genannt) die theoretische Grundlage für die statistische Analyse der Vermögenslage in der Gesamtheit öffentlicher Unternehmen dar. Die Vermögenslage wird mit Hilfe der aus der Bilanz ablesbaren Kennzahlen analysiert. Dabei stellen die Posten der Bilanz ursprüngliche Merkmale dar, auf deren Grundlage die zu untersuchenden Merkmale – Kennzahlen der Vermögenslage gebildet werden. Da die Heterogenität öffentlicher Unternehmen die Vergleichbarkeit der untersuchten Kennzahlen erschwert, stellt die Aufbereitung der Bilanz (Bildung der Strukturbilanz) in diesem Zusammenhang einen wichtigen Zwischenschritt in der Analyse dar, der allerdings schon dem Wirtschaftsprüfer erhebliche Kopfschmerzen bereiten kann, geschweige dem Statistiker. Eine einheitliche Strukturbilanz soll die Vergleichbarkeit der Bilanzkennzahlen gewähren. Die Vorgehensweise bei der Aufbereitung der Bilanz für eine Strukturbilanz wird in der Fachliteratur nicht eindeutig festgelegt. Die fachlichen Beiträge dort bestehen überwiegend aus Hinweisen und Empfehlungen zum Vorgehen in einzelnen Untenehmen, was natürlich gut nachzuvollziehen ist, da jedes Unternehmen eine eigene Spezifik hat. An dieser Stelle muss jedoch ein Statistiker, der sich weniger mit den einzelnen Fällen beschäftigt, sondern die Massenphänomene untersucht, auf eine einheitliche Variante der Bilanzaufbereitung zurückgreifen. Auf die Besonderheiten der Datenaufbereitung für öffentliche Unternehmen und die Bildung der Strukturbilanz soll an dieser Stelle nicht eingegangen werden. In dem folgenden Abschnitt werden die zu untersuchenden Merkmale - Kennzahlen der Vermögenslage definiert. Diesem schließt sich der Abschnitt mit den empirischen Ergebnissen an. Die Berechnungen wurden sowohl für die ganze Grundgesamtheit öffentlicher Unternehmen als auch an einigen Stellen für ihre einzelnen Klassen durchgeführt.
Background: Leishmania tarentolae, a unicellular eukaryotic protozoan, has been established as a novel host for recombinant protein production in recent years. Current protocols for protein expression in Leishmania are, however, time consuming and require extensive lab work in order to identify well-expressing cell lines. Here we established an alternative protein expression work-flow that employs recently engineered infrared fluorescence protein (IFP) as a suitable and easy-to-handle reporter protein for recombinant protein expression in Leishmania. As model proteins we tested three proteins from the plant Arabidopsis thaliana, including a NAC and a type-B ARR transcription factor. Results: IFP and IFP fusion proteins were expressed in Leishmania and rapidly detected in cells by deconvolution microscopy and in culture by infrared imaging of 96-well microtiter plates using small cell culture volumes (2 μL - 100 μL). Motility, shape and growth of Leishmania cells were not impaired by intracellular accumulation of IFP. In-cell detection of IFP and IFP fusion proteins was straightforward already at the beginning of the expression pipeline and thus allowed early pre-selection of well-expressing Leishmania clones. Furthermore, IFP fusion proteins retained infrared fluorescence after electrophoresis in denaturing SDS-polyacrylamide gels, allowing direct in-gel detection without the need to disassemble cast protein gels. Thus, parameters for scaling up protein production and streamlining purification routes can be easily optimized when employing IFP as reporter. Conclusions: Using IFP as biosensor we devised a protocol for rapid and convenient protein expression in Leishmania tarentolae. Our expression pipeline is superior to previously established methods in that it significantly reduces the hands-on-time and work load required for identifying well-expressing clones, refining protein production parameters and establishing purification protocols. The facile in-cell and in-gel detection tools built on IFP make Leishmania amenable for high-throughput expression of proteins from plant and animal sources.
Bei der Suche nach Möglichkeiten, die Weiterbildung für Informatiklehrkräfte auszubauen, bietet sich der Einsatz virtueller Lernräume an. Dieses Papier berichtet über ein Projekt, in dem ein exemplarischer virtueller Lernraum für kollaboratives Lernen in der Lehrerweiterbildung in Informatik theoriegeleitet erstellt, erprobt und bewertet wurde. Die erzielten Ergebnisse über das Nutzungsverhalten können für weitere E-Learningprojekte in der Lehrerbildung hilfreich sein. Der Schwerpunkt dieses Papiers liegt auf der Gestaltung des Lernraums unter Beachtung der speziellen Situation der Informatiklehrkräfte, nicht auf der didaktischen Aufbereitung der betreffenden Lerneinheit.
Think local sell global
(2010)
Aus dem Inhalt: 1. Einleitung 2. Der deutsche Wohlfahrtsstaat im internationalen Vergleich 2.1 Das liberale Wohlfahrtsregime und der Prototyp USA 2.2 Das sozialdemokratische Wohlfahrtsregime und der Prototyp Schweden 2.3 Das konservative Wohlfahrtsregime und der Prototyp Deutschland 3. Kinderarmut im Spiegel der Sozialpolitik 4. Kinderarmut als familienpolitische Herausforderung 5. Fazit und Ausblick
ERP-Architekturen
(2010)
Fire prone Mediterranean-type vegetation systems like those in the Mediterranean Basin and South-Western Australia are global hot spots for plant species diversity. To ensure management programs act to maintain these highly diverse plant communities, it is necessary to get a profound understanding of the crucial mechanisms of coexistence. In the current literature several mechanisms are discussed. The objective of my thesis is to systematically explore the importance of potential mechanisms for maintaining multi-species, fire prone vegetation by modelling. The model I developed is spatially-explicit, stochastic, rule- and individual-based. It is parameterised on data of population dynamics collected over 18 years in the Mediterranean-type shrublands of Eneabba, Western Australia. From 156 woody species of the area seven plant traits have been identified to be relevant for this study: regeneration mode, annual maximum seed production, seed size, maximum crown diameter, drought tolerance, dispersal mode and seed bank type. Trait sets are used for the definition of plant functional types (PFTs). The PFT dynamics are simulated annual by iterating life history processes. In the first part of my thesis I investigate the importance of trade-offs for the maintenance of high diversity in multi-species systems with 288 virtual PFTs. Simulation results show that the trade-off concept can be helpful to identify non-viable combinations of plant traits. However, the Shannon Diversity Index of modelled communities can be high despite of the presence of ‘supertypes’. I conclude, that trade-offs between two traits are less important to explain multi-species coexistence and high diversity than it is predicted by more conceptual models. Several studies show, that seed immigration from the regional seed pool is essential for maintaining local species diversity. However, systematical studies on the seed rain composition to multi-species communities are missing. The results of the simulation experiments, as presented in part two of this thesis, show clearly, that without seed immigration the local species community found in Eneabba drifts towards a state with few coexisting PFTs. With increasing immigration rates the number of simulated coexisting PFTs and Shannon diversity quickly approaches values as also observed in the field. Including the regional seed input in the model is suited to explain more aggregated measures of the local plant community structure such as species richness and diversity. Hence, the seed rain composition should be implemented in future studies. In the third part of my thesis I test the sensitivity of Eneabba PFTs to four different climate change scenarios, considering their impact on both local and regional processes. The results show that climate change clearly has the potential to alter the number of dispersed seeds for most of the Eneabba PFTs and therefore the source of the ‘immigrants’ at the community level. A classification tree analysis shows that, in general, the response to climate change was PFT-specific. In the Eneabba sand plains sensitivity of a PFT to climate change depends on its specific trait combination and on the scenario of environmental change i.e. development of the amount of rainfall and the fire frequency. This result emphasizes that PFT-specific responses and regional process seed immigration should not be ignored in studies dealing with the impact of climate change on future species distribution. The results of the three chapters are finally analysed in a general discussion. The model is discussed and improvements and suggestions are made for future research. My work leads to the following conclusions: i) It is necessary to support modelling with empirical work to explain coexistence in species-rich plant communities. ii) The chosen modelling approach allows considering the complexity of coexistence and improves the understanding of coexistence mechanisms. iii) Field research based assumptions in terms of environmental conditions and plant life histories can relativise the importance of more hypothetic coexistence theories in species-rich systems. In consequence, trade-offs can play a lower role than predicted by conceptual models. iv) Seed immigration is a key process for local coexistence. Its alteration because of climate change should be considered for prognosis of coexistence. Field studies should be carried out to get data on seed rain composition.