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The Mask Metempsychosis: Reinventing Cultural Icons
No full textApart from the author's personal interest in phenomena dealing with the construction, negotiation, maintenance, manipulation and reification of personal and public identity, this work is based on consistent recent confirmations of masks not only being 'alive and well' in popular culture as well as in (social) media, but in fact articulating socio-political power in ways not unlike those of their archaic prototypes. Therefore, one aim pursued herein is the tracing of an evolution of masks in the Western collective consciousness, across several outstanding epochs and genres, which we have linked together in order to better visualise performance, reception and interaction trends leading up to the present. Another aim of this research is the introduction of new patterns and categories as conceptual tools for further investigation, beginning with defining the Mask Metempsychosis process itself and discussing its three phases in specific contexts of cultural history, as indicated above. Thirdly, mask-wearing archetypes of folklore and more recent fiction will be analysed throughout, together with outstanding characters they have engendered, based on the previously set two layers of reception. The reader shall thus gain further insight into masks' articulation of power and aesthetics as part of the complex everyday and ceremonial negotiations of private and public, self and community, as well as of the socio-political with the religious and the psychological
Theoretical Study of the Interaction of Amphiphilic Block Co-polymers with Biological Interfaces and Small Molecules
No full textSynthetic polymers are versatile materials with an extraordinary range of technological applications playing essential and ubiquitous roles in everyday life. Presently, the applications of polymers are not limited to traditional areas of technology but extend to novel uses in the areas of nanotechnology connected to medicine and pharmacology. Polyethylene oxide (PEO) and polypropylene oxide (PPO) homo-polymers as well as the block co-polymers based on them (Pluronics or Poloxamers) are among the most versatile polymers used in these fields. These polymers have the advantages of being non-toxic, easily available, economic and customizable to meet specific purposes. Despite many experimental and theoretical studies on them, the actual mechanisms of their interactions with bio-systems and drug molecules are still unknown. The research work reported in this PhD thesis is aimed to understand the behavior of these polymers in solution and their interactions with biological interfaces and drug molecules using molecular dynamics simulations. Recently proposed models for the ether based polymers and their monomers were successfully tested in a wide range of non-aqueous solvents to establish their versatility. The thermodynamics and kinetics of the polymers and the monomers were first studied at simple water/n-heptane interface. Eventually the research was extended to study their properties at lipid bilayer interfaces. The percolation behavior of the ether based polymers and their monomers were studied using standard molecular dynamics, steered molecular dynamics and umbrella sampling simulations. It has been shown that the percolation of PPO chains through lipid bilayer is favored compared to their PEO counterparts. PEO chains do not have any preference for the interior of the bilayer and but the PPO chains prefer to stay inside the bilayer. PPO chains with length comparable to the width of the bilayer tend to span across the bilayer. Pluronics also show similar effect with PPO parts spanned along the width of the bilayer and the PEO blocks in the polar headgroup region and water in both sides of the bilayer. The potential of mean force barriers of bilayer percolation were found to be smaller for PPO chains of all lengths than their PEO counterparts. The last part of the project aimed to investigate the mechanism of interaction of Pluronics with hydrophobic drug molecules. Curcumin, a natural drug from the Indian spice turmeric, has recently attracted interest as potential multivalent drug for the treatment of different diseases comprising cancer and Alzheimer's disease. For its hydrophobic nature, it has low solubility in water and therefore efforts are directed to find suitable polymeric carrier. For all these reason, Curcumin was chosen as model of hydrophobic drug for my study. A suitable force field model for this drug was optimized and used to study its interaction with Pluronics. The results of these MD simulation studies evidenced the mechanism of drug-polymer aggregate formation in which Curcumin is embedded into a hydrophobic PPO core surrounded by a hydrophilic PEO shell. The findings of this thesis are useful in the better understanding of the interactions of block co-polymers with bio-membranes at atomic level. Moreover, they provide a better insight on the dynamics and thermodynamics of the drug encapsulation and delivery across cell membranes
Characterization of aspherical lenses by experimental ray tracing
No full textAspherical lenses are widely used in different applications of modern high quality optics, due to their good optical performance and their potential to reduce the weight and size of the optical systems. Substantial progress in the production technologies of aspherical lenses in the last decade increases the demand on accurate and reliable measurement systems for aspherical surfaces. So far, different measurement methods such as interferometry, Shack-Hartmann wavefront sensors and tactile surface profiling have been proposed. However, because of the complex surface profiles of the aspherical lenses, these methods have significant limitations concerning dynamic range and flexibility. The goal of non-contact measurement of the surfaces of the aspherical lenses without a reference object (null lens or computer generated holograms) is still not achieved.
In this thesis, the potential and the limitations of the “experimental ray tracing” (ERT) method for characterization of aspherical lenses are investigated. A new approach called “aspherical surface retrieval” (ASR) based on the ERT method is proposed. This approach allows retrieval of the aspherical surface profile of the lens from the measured slopes of the transmitted rays. In addition, simultaneous measurement of the optical performance of aspherical lenses and the aspherical surface profiles within a single test unit is targeted.
Throughout the thesis work, an ERT setup is realized and a software is developed for complete automation of the setup and analysis of the measurement data. The wavefront aberrations are determined using zonal and modal wavefront reconstruction methods. The coefficients of the Zernike polynomials that are fitted to the measurement data are used to determine the focal length. In the ASR approach, the relationship between the slopes of the transmitted rays and the aspherical surface profile is derived. Furthermore, a numerical ray tracing algorithm is written for comparison of the actual and the model aspherical lens. An optimization process minimizing the difference between the actual and the model aspherical lens is used to retrieve the aspherical surface profile. Moreover, the proof-of-principle of the ASR approach is demonstrated using simulations.
A Mach-Zehnder interferometer and a Shack-Hartmann wavefront sensor measurement setup is realized for the comparison of the measurements of wavefront aberrations of commercial aspherical lenses with the ERT setup. The measurement results using the ASR approach are verified by the measurements of different aspherical lenses by a commercial tactile surface profiler. The proposed approach based on the ERT method allowed simultaneous measurements of the optical performance and the aspherical surface profile of the lenses
Bioinformatic analyses of genomes, metagenomes and expression data of polysaccharide-degrading marine microbes
No full textNowadays, sequence-based methods like genomics, metagenomics, and metatranscriptomics are standard approaches for the investigation of biodiversity, functionality and gene activities of organisms and their roles in a specific ecosystem. In the MIMAS (“Microbial Interactions in MArine Systems”) project, a combination of these methods was used to investigate seasonal changes in the microbial community in the German Bight.
In this thesis, I developed read-based mapping tools to analyze the MIMAS sequence data. First, a taxonomic classification tool to classify metagenomic sequences by mapping them to publicly available reference genomes and thus linking functional sequence data with taxonomy. The mapping of metagenomic reads taken in 2009, onto genomes isolated from the North Sea in 2010, revealed their ecological relevance. The second tool developed was an analysis pipeline to assign function and taxonomy to metatranscriptomic data. With the help of these tools shifts in the microbial community composition and functional adaptations to the changes in nutrient supply could be analyzed. The third part of my thesis was a genome study of Formosa agariphila, isolated from a green algae in the Sea of Japan. The analysis of the genome, revealed high numbers of CAZymes, enzymes involved in the creation, degradation, and modification of glycosidic bonds in carbohydrates. An complementary analysis of two North Sea Formosa strains showed different CAZyme profiles, which indicate different lifestyles. As a result of these analyses it could be shown that the CAZyme repertoire of an organism can serve as a niche-defining characteristic.
The bioinformatic analyses of (meta)genomic and expression data are necessary to strengthen the understanding of microbial communities under changing environmental conditions. The tools and methods developed and described in this thesis were an important part of the analyses and will enable further studies investigating marine microbial communities
Influence of Seabed Topography on Cold-Water Coral Distribution and Habitat Suitability
No full textCold-water coral (CWC) Lophelia pertusa is the dominant reef framework-builder in the North Atlantic, with the reefs known as biodiversity hotspots on continental margin. Gorgonians Paragorgia arborea and Primnoa resedaeformis add significant habitat complexity to benthic environment, and support a host of invertebrate species. These CWCs are vulnerable to anthropogenic impacts such as bottom trawling. Investigating CWC distribution in relation to seabed topography is important for understanding the terrain influence on coral distribution. Further development of predictive habitat models may help to understand their potential distribution. In this study, the observed distribution of L. pertusa, P. arborea and P. resedaeformis in relation to multiscale terrain variables at three reef complexes (the Rost, Sotbakken and Traena) on the Norwegian margin were investigated using Ecological Niche Factor Analysis (ENFA), Jackknife tests and linear regression. Habitat suitability for the CWCs were predicted using Maximum Entropy model (MaxEnt), Genetic Algorithm for Rule-set Production (GARP) and ENFA based on the multiscale terrain variables. The observed distribution of P. arborea and P. resedaeformis at the three study sites, and their abundances at Sotbakken Reef were most strongly correlated with curvature and bathymetric position index at the analysis scales of 90 m or 170 m. Additionally, P. arborea distribution was strongly correlated with aspect (90 m) at Rost Reef, whilst both gorgonian species distribution strongly correlated with rugosity (30 m) at Traena Reef. The abundance/distribution of L. pertusa was strongly correlated with most of the investigated terrain variables, particularly variables at larger scales at Sotbakken Reef - slope and profile curvature (310 m), aspect and plan curvature (170 m), and variables at middle scales at Traena Reef - plan curvature (50 m and 90 m), aspect and slope (50 m). Both P. arborea and P. resedaeformis tended to inhabit local topographic highs across all three sites, probably to benefit from the higher food flux available in such locations, and limited by the soft sediment widely distributed at Sotbakken Reef and Traena Reef. ii Suitable habitats for both gorgonian species at Rost Reef were predicted to occur mainly on the upper section of the large slide and along the ridges, with suitable habitat for P. arborea particularly on the eastern side of the large ridges, indicating strongly influenced by the prevalent bottom current in a NW flowing direction. The predicted suitable habitat for L. pertusa was predominantly on the easterly tips of the reef structures, with this unidirectional reef development may well be related to the west flowing prevalent bottom current. The evaluation of habitat predictions show that all three algorithms performed significantly better than random with MaxEnt predictions outperforming ENFA and GARP predictions. This study contributes to the understanding of how seabed topography could influence the distribution of CWCs, and the successful predictions of habitat suitability for CWCs based on multiscale terrain variables at local scales. Further comparative study including additional environmental controls on coral distribution would probably lead to more precise predictions; with this study over a wider area may be beneficial for protection of these habitats
Novel SF5- and CF3-containing organyls
No full textThe limitation of pentafluoro-λ6-sulfanyl (SF5) sources and building blocks stimulates great interest for investigating new approaches for synthesizing of SF5-containing compounds. The properties of the SF5-group often are compared with those of the CF3-group and the “advantages” of the SF5-group were hence referred to as a “super CF3-function”.
In this work, new synthetic routes towards SF5 and CF3 containing aromatics are presented. The first route is the radical addition of SF5Cl and CF3I to double bonds of 7-oxabicyclo[2.2.1]hept-2-ene derivatives, the second approach shows an improved method for the synthesis and followed by fluorination of arylsulfur chlorotetrafluorides to give arylsulfur pentafluorides. Key steps of the synthetic sequence for the first approach were based upon radical addition reactions of SF5Cl or CF3I as sources of SF5- and CF3-groups, to the double bond of different 7-oxabicyclo[2.2.1]hept-2-ene derivatives. Dehydrohalogenation followed by aromatization leads to pentafluorosulfanyl and trifluoromethyl aromatics, respectively.
The second synthetic route is the fluorination of arylsulfur chlorotetrafluorides to yield arylsulfur pentafluorides. Treatment of different aryl thiols and diaryl disulfides with chlorine and potassium fluoride provides the corresponding arylsulfur chlorotetrafluorides. The application of new conditions using KHF2 and TFA converts these compounds to arylsulfur pentafluorides
Finding levers for innovation in diverse teams
No full textHow do diverse teams come into existence? Are they allocated to the right kind of tasks? How do elderly stereotypes influence age diverse groups? How can different pathways towards creativity be switched on or off? What makes diversity training effective? And what role do different creativity dimensions, such as fluency, originality, flexibility, depth or nationality related and nationality unrelated creativity, play in assessing all the above? The theoretical and empirical work presented in this dissertation addresses the above questions and shows that team creativity is a complex issue, even more so if coupled with team diversity.
First, this dissertation investigates age-related differences with regard to team staffing decisions. Accordingly, older individuals were better able to match task type (e.g. simple or complex/creative tasks) and team diversity level (homogeneous or heterogeneous).
Second, in four-person groups consisting of two younger and two older adults, elderly stereotypes were manipulated. This thesis finds that the creative fluency of highly conscientious age-diverse teams was higher when elderly stereotypes were positive, and respectively lower for the control group and the negative age-stereotype condition. For depth, a creativity dimension relying on perseverance, the effects were diametrically reversed.
Third, this thesis finds that a team's actual nationality diversity (i.e., the possibility to apply the training) as well as the diversity beliefs of the team members (i.e., the personal need for the training) interact in determining group creativity following a diversity training. Accordingly, teams with relatively low levels of diversity beliefs benefitted most from a diversity training, provided that they could actually use the training in their nationality diverse team.
In sum, many factors including personality, age, and beliefs have to be taken into account. The path to achieving creativity in diverse teams is more difficult and paved with more obstacles than it is the case for homogeneous teams, but at the same time team diversity is the much more promising route to take
3D High Resolution Numerical Modeling of Hydrothermal Plumes
No full textHydrothermal plumes form along mid-ocean ridges where seawater exchanges heat and chemical components with the hot rock and is injected back into the ocean as hot, mineral-rich and buoyant fluid. We take a numerical modeling approach to study the dynamics of hydrothermal plumes with the 3D time-dependent, Eulerian, adaptive mesh refinement code {\sc Gerris}. We have implemented a new module into Gerris that treats buoyancy-driven turbulence by means of a subgrid mode. First we simulate hydrothermal plumes in a static environment and the entrainment coefficient that we deduce from simulations falls into the range of the experimentally determined values, but the ratio between the level of the neutral buoyancy and the maximum plume height are found to be higher than the one predicted by the integral models. This difference will lead to a substantially different heat flux estimation. We also measure the radial profile of the plume and calculate the concentration-to-velocity width ratio which agrees very well with the laboratory measured value. Then we explore the importance of background currents and find a similar difference between the 3D simulations and integral models over the rising height, just as the static case. We further prove that a significant fraction of this difference can be explained by the ignorance of the turbulent transport of the latter. Clustered vents appear in many hydrothermal systems. We simulate systems with different clustering configurations to study the effects of clustering. In addition to studying the far field properties of hydrothermal plumes such as the rising height, we implement a near-field numerical experiment to simulate and validate a speed meter device used in in-situ hydrothermal volume flux measurement and find it needs correction when applied to high temperature plumes. In the end we implement an artificial reaction between plume fluid and seawater with a virtual reaction rate and investigate the dependence of reaction intensity on the fluid concentration and mixing. Our high resolution simulations provide a reliable and also flexible modeling approach to model the hydrothermal plumes in complicated environment with the potential to cooperate with the state of the art field researches
Hours of service regulations in the United States and the 2013 rule change
No full textThis paper studies the revised hours of service regulations for truck drivers in the United States which will enter into force in July 2013. It provides a detailed model of the new regulation and presents and a new simulation-based method to assess the impact of the rule change on operational costs and road safety. Unlike previous methodologies, the new methodology takes into account that carriers can use optimization as a tool to minimize the economic impact of stricter regulations. Simulation experiments are conducted indicating that the monetized safety benefit of reducing the daily driving time limits is on the same order of magnitude compared to the additional operational costs
European Health Divide Revisited : Health in Transition Countries and Beyond
No full textHealth is one of the most essential assets of an individual or society, yet throughout time it has developed very differently in various parts of the world. In Europe, the understanding of health has traditionally been regionally divided between the West and East, but is this divide still present? Better understanding health and what determines it in Eastern and Western Europe enables me to revisit the health divide on the continent.
Among the plethora of literature on the determinants of health, one can clearly identify two main approaches. One approach analyses mostly how the objective indicators influence objective health at the country level; another deals with primarily subjective individual-level health and its subjective determinants. Very rarely, however, do the approaches intersect. This thesis incorporates the different approaches to the determinants of health in order to determine whether a) the objective and subjective health indicators are similar or different, and if they could be used interchangeably; b) the objective and subjective determinants influence health differently; c) both the individual and contextual factors affect health; and d) the European health divide has changed over the past two decades of transition.
To do that, the thesis adopts primarily a quantitative approach in the five empirical studies, united under one theoretical umbrella. In the detailed literature review, the main theoretical framework of the augmented health production function is developed and used throughout the thesis. A variety of methods—from cluster and factor analysis to ordinary least squares (OLS), panel, and multilevel regressions—is used in the different chapters of the thesis. The analysis is carried out with the help of six different datasets, providing data at different levels. First, three studies concentrate on the 28 Central and East European (CEE) countries, while the other two focus on the broader European context. In the first four chapters, health is the centre of the story, modelled within the augmented production function. The final study directly assesses the changes in the European health divide at the macro level.
This detailed and extensive analysis provides important answers to the set research questions. First, I find that the objective and subjective health indicators are determined very differently, and therefore, regardless of how similar they may seem, should not be used interchangeably. Second, subjective and objective factors have a different effect on health, and they should both be included when health is analysed. Third, contextual effects on individual health are very weak. This is particularly true for the CEE countries. Finally, over years of transition, the European health divide has changed to a ‘West-Central-East’ design. Therefore, revisiting our understanding of what “East” and “West” mean in terms of health in Europe is in order.
These findings enhance the literature on the determinants of health by bridging the two diverging approaches and creating a theoretical framework—augmented health production function—for analysing the determinants of health, which can be further tested in other regions of the world. While the divide in Europe—still often referred to as “East-West”—has changed, this divide could adjust our whole understanding of European health patterns