Approaches to studying smectic layer elasticity and field induced deformations

The initial aim of the work presented in this thesis was to examine smectic layer compressibility with a view to improving our understanding of the stability of intermediate phases. A natural starting point was to investigate the smectic-A phase, as it is the most basic of the smectic phases. The response of the layered structure to external fields is also a focus of this thesis as electric and magnetic fields enable the layer properties to be probed. Investigations into the reorientation dynamics of smectic-A layers in magnetic fields were performed using geometries and cell thicknesses (>50 μm) that are not feasible using electric fields. Data presented in this thesis show that three distinct reorientation mechanisms can occur, one of which is previously unreported and bridges the gap between the previously known mechanisms. The new mechanism observed in 270 μm and 340 μm thickness cells exhibits multiple stage reorientation on a timescale between tens and hundreds of seconds. Using conventional electro-optic techniques combined with a theoretical approach developed by others, this thesis presents a new technique to provide measurement of relative smectic layer compressibility of eight smectic-A liquid crystalline materials. The method presented here combines data on cell thickness, dielectric anisotropy and the measurement of the voltage threshold of the toroidal to stripe domain transition. As expected, the experimental data indicated that materials with shorter molecular lengths had the largest relative layer compressibility. Finally, direct measurement of smectic layer compressibility was investigated and the design of an apparatus capable of such measurements was undertaken. Preliminary results from such an apparatus are presented along with a discussion on the steps taken to develop the design.EThOS - Electronic Theses Online ServiceEPSRCGBUnited Kingdo

Sich selbst vergleichen. Zur Relationalität autobiographischen Schreibens vom 12. Jahrhundert bis zur Gegenwart

Arlinghaus F-J, Erhart W, Gumpert L, Siemianowski S. Sich selbst vergleichen. Zur Relationalität autobiographischen Schreibens vom 12. Jahrhundert bis zur Gegenwart. Histoire. Vol 179 1st ed. Bielefeld: transcript Verlag; 2020.Wer das eigene Leben beschreibt, vergleicht sich mit anderen und mit sich selbst: Unter diesem Gesichtspunkt nehmen die vier Wissenschaftler*innen aus unterschiedlichen Disziplinen die Geschichte des autobiographischen Schreibens neu in den Blick. Leitend ist dabei die Erkenntnis, dass in Selbstbeschreibungen nicht ein vermeintlich autonomes Ich im Mittelpunkt steht, sondern ein stets in Beziehung stehendes relationales Selbst. Wie sich solche Individualität durch das Sich-Selbst-Vergleichen auf historisch jeweils unterschiedliche Weise herstellt, wird anhand von Autor*innen wie Petrus Abaelard, Guibert von Nogent, Giovanni di Pagolo Morelli, Jean-Jacques Rousseau, Johann Wolfgang von Goethe, Bertha von Suttner, Walter Benjamin, Roland Barthes, Didier Eribon und vielen anderen analysiert

Heterologous expression of the yeast Tpo1p or Pdr5p membrane transporters in Arabidopsis confers plant xenobiotic tolerance

This deposit is composed by the main article plus the supplementary materials of the publication.Soil contamination is a major hindrance for plant growth and development. The lack of effective strategies to remove chemicals released into the environment has raised the need to increase plant resilience to soil pollutants. Here, we investigated the ability of two Saccharomyces cerevisiae plasma-membrane transporters, the Major Facilitator Superfamily (MFS) member Tpo1p and the ATP-Binding Cassette (ABC) protein Pdr5p, to confer Multiple Drug Resistance (MDR) in Arabidopsis thaliana. Transgenic plants expressing either of the yeast transporters were undistinguishable from the wild type under control conditions, but displayed tolerance when challenged with the herbicides 2,4-D and barban. Plants expressing ScTPO1 were also more resistant to the herbicides alachlor and metolachlor as well as to the fungicide mancozeb and the Co(2+), Cu(2+), Ni(2+), Al(3+) and Cd(2+) cations, while ScPDR5-expressing plants exhibited tolerance to cycloheximide. Yeast mutants lacking Tpo1p or Pdr5p showed increased sensitivity to most of the agents tested in plants. Our results demonstrate that the S. cerevisiae Tpo1p and Pdr5p transporters are able to mediate resistance to a broad range of compounds of agricultural interest in yeast as well as in Arabidopsis, underscoring their potential in future biotechnological applications.Fundação para a Ciência e a Tecnologia grants: (EXPL/AGR-PRO/1013/2013, PTDC/BIA-PLA/1084/2014, SFRH/BPD/44640/2008, SFRH/BPD/81221/2011, PD/BD/105735/2014, PD/00133/2012, SFRH/BD/92552/2013, UID/BIO/04565/2013, UID/Multi/04551/2013). Programa Operacional Regional de Lisboa 2020 grant: (Project N. 007317).info:eu-repo/semantics/publishedVersio