Smallholder Farmers and Collective Action: What Determines the Intensity of Participation?

Farm Management,

Development of new approaches for characterising DNA origami-based nanostructures with atomic force microscopy and super-resolution microscopy

DNA nanotechnology has developed a versatile set of methods to utilise DNA self-assembly for the bottom-up construction of arbitrary two- and three-dimensional DNA objects in the nanometre size range, and to functionalise the structures with unprecedented site-specificity with nanoscale objects such as metallic and semiconductor nanoparticles, proteins, fluorescent dyes, or synthetic polymers. The advances in structure assembly have resulted in the application of functional DNA-based nanostructures in a gamut of fields from nanoelectronic circuitry, nanophotonics, sensing, drug delivery, to the use as host structure or calibration standard for different types of microscopy. However, the analytical means for characterising DNA-based nanostructures drag behind these advances. Open questions remain, amongst others in quantitative single-structure evaluation. While techniques such as atomic force microscopy (AFM) or transmission electron microscopy (TEM) offer feature resolution in the range of few nanometres, the number of evaluated structures is often limited by the time-consuming manual data analysis. This thesis has introduced two new approaches to quantitative structure evaluation using AFM and super-resolution fluorescence microscopy (SRM). To obtain quantitative data, semi-automated computational image analysis routines were tailored in both approaches. AFM was used to quantify the attachment yield and placement accuracy of poly(3-tri(ethylene glycol)thiophene)-b-oligodeoxynucleotide diblock copolymers on a rectangular DNA origami. This work has also introduced the first hybrid of DNA origami and a conjugated polymer that uses a highly defined polythiophene derivative synthesised via state-of-the-art Kumada catalyst-transfer polycondensation. Among the AFM-based studies on polymer-origami-hybrids, this was the first to attempt near-single molecule resolution, and the first to introduce computational image analysis. Using the FindFoci tool of the software ImageJ revealed attachment yields per handle between 26 - 33%, and determined a single block copolymer position with a precision of 80 - 90%. The analysis has pointed out parameters that potentially influence the attachment yield such as the handle density and already attached objects. Furthermore, it has suggested interactions between the attached polymer molecules. The multicolour SRM approach used the principles of single-molecule high-resolution co-localisation (SHREC) to evaluate the structural integrity and the deposition side of the DNA origami frame “tPad” based on target distances and angles in a chiral fluorophore pattern the tPads were labelled with. The computatinal routine that was developed for image analysis utilised clustering to identify the patterns in a sample’s signals and to determine their characteristic distances and angles for hundreds of tPads simultaneously. The method excluded noise robustly, and depicted the moderate proportion of intact tPads in the samples correctly. With a registration error in the range of 10 -15 nm after mapping of the colour channels, the precision of a single distance measurements on the origami appeared in the range of 20 - 30 nm. By broadening the scope of computational AFM image analysis and taking on a new SRM approach for structure analysis, this work has presented working approaches towards new tools for quantitative analysis in DNA nanotechnology. Furthermore, the work has presented a new approach to constructing hybrid structures from DNA origami and conjugated polymers, which will open up new possibilities in the construction of nanoelectronic and nanophotonic structures

Intra- and intercellular fluctuations in Min-protein dynamics decrease with cell length

Self-organization of proteins in space and time is of crucial importance for the functioning of cellular processes. Often, this organization takes place in the presence of strong random fluctuations due to the small number of molecules involved. We report on stochastic switching of the Min-protein distributions between the two cell halves in short Escherichia coli cells. A computational model provides strong evidence that the macroscopic switching is rooted in microscopic noise on the molecular scale. In longer bacteria, the switching turns into regular oscillations that are required for positioning of the division plane. As the pattern becomes more regular, cell-to-cell variability also lessens, indicating cell length-dependent regulation of Min-protein activity.Comment: Article and Supplementary Information: 26 pages, 12 figure

Diagnostic argumentation in teacher education: Making the case for justification, disconfirmation, and transparency

Research on diagnosing in teacher education has primarily emphasized the accuracy of diagnostic judgments and has explained it in terms of factors such as diagnostic knowledge. However, approaches to scientific argumentation and information processing suggest differentiating between diagnostic judgment and diagnostic argumentation: When making accurate diagnostic judgments, the underlying reasoning can remain intuitive, whereas diagnostic argumentation requires controlled and explicable reasoning about a diagnostic problem to explain the reasoning in a comprehensible and persuasive manner. We suggest three facets of argumentation for conceptualizing diagnostic argumentation, which are yet to be addressed in teacher education research: justification of a diagnosis with evidence, disconfirmation of differential diagnoses, and transparency regarding the processes of evidence generation. Therefore, we explored whether preservice teachers’ diagnostic argumentation and diagnostic judgment might represent different diagnostic skills. We also explored whether justification, disconfirmation, and transparency should be considered distinct subskills of preservice teachers’ diagnostic argumentation. We reanalyzed data of 118 preservice teachers who learned about students’ learning difficulties with simulated cases. For each student case, the preservice teachers had to indicate a diagnostic judgment and provide a diagnostic argumentation. We found that preservice teachers’ diagnostic argumentation seldom involved all three facets, suggesting a need for more specific training. Moreover, the correlational results suggested that making accurate diagnostic judgments and formulating diagnostic argumentation may represent different diagnostic skills and that justification, disconfirmation, and transparency may be considered distinct subskills of diagnostic argumentation. The introduced concepts of justification, disconfirmation, and transparency may provide a starting point for developing standards in diagnostic argumentation in teacher education

Extracellular RNA as a Versatile DAMP and Alarm Signal That Influences Leukocyte Recruitment in Inflammation and Infection

Upon vascular injury, tissue damage, ischemia, or microbial infection, intracellular material such as nucleic acids and histones is liberated and comes into contact with the vessel wall and circulating blood cells. Such "Danger-associated molecular patterns" (DAMPs) may thus have an enduring influence on the inflammatory defense process that involves leukocyte recruitment and wound healing reactions. While different species of extracellular RNA (exRNA), including microRNAs and long non-coding RNAs, have been implicated to influence inflammatory processes at different levels, recent in vitro and in vivo work has demonstrated a major impact of ribosomal exRNA as a prominent DAMP on various steps of leukocyte recruitment within the innate immune response. This includes the induction of vascular hyper-permeability and vasogenic edema by exRNA via the activation of the "vascular endothelial growth factor" (VEGF) receptor-2 system, as well as the recruitment of leukocytes to the inflamed endothelium, the M1-type polarization of inflammatory macrophages, or the role of exRNA as a pro-thrombotic cofactor to promote thrombosis. Beyond sterile inflammation, exRNA also augments the docking of bacteria to host cells and the subsequent microbial invasion. Moreover, upon vessel occlusion and ischemia, the shear stress-induced release of exRNA initiates arteriogenesis (i.e., formation of natural vessel bypasses) in a multistep process that resembles leukocyte recruitment. Although exRNA can be counteracted for by natural circulating RNase1, under the conditions mentioned, only the administration of exogenous, thermostable, non-toxic RNase1 provides an effective and safe therapeutic regimen for treating the damaging activities of exRNA. It remains to be investigated whether exRNA may also influence viral infections (including COVID-19), e.g., by supporting the interaction of host cells with viral particles and their subsequent invasion. In fact, as a consequence of the viral infection cycle, massive amounts of exRNA are liberated, which can provoke further tissue damage and enhance virus dissemination. Whether the application of RNase1 in this scenario may help to limit the extent of viral infections like COVID-19 and impact on leukocyte recruitment and emigration steps in immune defense in order to limit the extent of associated cardiovascular diseases remains to be studied

Chancen und Herausforderungen der internationalen Migration von Pflegepersonen im Krankenhaus

Pflegepersonen mit Migrationshintergrund stellen ein wichtiges aktuelles und zukünftiges Beschäftigungspotential in der Pflege dar. Dies gilt für Österreich ebenso wie im internationalen Kontext. Laut den Angaben der WHO (Weltgesundheitsorganisation) sind zurzeit etwa 14,5 % der in Österreich beschäftigten Pflegepersonen im Ausland geboren, was im internationalen Vergleich einen relativ hohen Anteil darstellt. Insgesamt betrachtet wird der Bedarf an Gesundheitsfachkräften mit Migrationshintergrund in vielen Ländern in Zukunft weiter vorhanden sein beziehungsweise noch steigen. Dieser erhöhte Bedarf ergibt sich vor allem aus der demographischen Entwicklung, verbunden mit einer allgemeinen Bevölkerungsalterung und einem Schrumpfen der Erwerbsbevölkerung, welche die Europäische Region vor zahlreiche wirtschaftliche, soziale und finanzielle Herausforderungen stellt. Die Entwicklung und Verbesserung politischer Handlungsmöglichkeiten in Zusammenhang mit der Migration von Gesundheitsfachkräften ist daher als höchst notwendig anzusehen. Im Kontext einer interkulturellen Pflege sind jedoch auch die Pflegewissenschaft, das Management im Pflegebereich, sowie alle Pflegepersonen und Patient/inn/en selbst gefordert, sich mit Migration auseinanderzusetzen. So ist beispielsweise auch der Spitalsalltag oft von einer migrationsspezifischen Vielfalt unter den Patient/inn/en und Pflegepersonen geprägt. Welche Chancen und Herausforderungen sich dabei für alle Beteiligten ergeben und wie diese Situation sowie der zukünftige Bedarf an Pflegepersonen mit Migrationshintergrund im Krankenhaus von Pflegedirektor/inn/en eingeschätzt wird, darüber gibt die vorliegende Diplomarbeit einen ersten Einblick. Auf Basis einer Literaturrecherche wurde hierfür eine Delphi - Befragung mit Pflegedirektor/inn/en aus Wien, Niederösterreich und dem Burgenland durchgeführt, woraus sich insgesamt ein sehr heterogenes Gesamtbild zeigt, das Vor- und Nachteile einer interkulturellen Pflegesituation widerspiegelt und eine erste Einschätzung möglicher zukünftiger Entwicklungen ermöglicht.Migration of specialized nursing staff is a social phenomenon which occurs in context of increasing global mobility and a growing competition for skills needed in the healthcare sector. Immigration of specialized nursing staff is needed in Austria as well as in many other countries in the European Region. About 14,5 per cent of all nurses currently employed in Austria are foreign-born according to the WHO (World Health Organization). By international standards this is a relatively high proportion. Altogether the number of specialized nursing staff in migration continues to increase each year. This growing demand is caused by demographic change, including an aging population and a shrinking labour force. Cross-border mobility of specialized nursing staff thus may be a symptom of deeper labour force-related problems in the countries of origin and / or the destination countries, which pose numerous challenges for related policies in these countries. The development and improvement of policies related to migration of specialized nursing staff must therefore be considered highly necessary. Intercultural nursing situations also call for nursing science, the management in the health care sector, as well as patients and nurses themselves to engage in the issue of migration. For instance, migratory diversity among patients and among staff members is a common feature in Austria´s hospitals. A number of chances and challenges occur in this context for all parties concerned. This master thesis gives an overview of how such intercultural nursing situations are evaluated by nursing-directors and how they estimate future demand for immigration of specialized nursing staff in Austria´s hospitals. Based on theoretical research a Delphi - survey was performed with nursing- directors in Vienna, Lower Austria and Burgenland. The results show a heterogeneous picture, reflecting advantages and disadvantages of intercultural nursing, and permit for a preliminary assessment of future developments in this sector

Tier - Geist - Moral

Die vorliegende Arbeit widmet sich der Naturforschung als Beitrag zur Ethik, im Besonde-ren zur Tierethik als Weichenstelle für die Art der Begründung in der Ethik überhaupt. Ausgehend vom antiken Weltbild beseelter Lebewesen, über das neuzeitliche Weltbild des Substanzdualismus René Descartes´ führt der Ablauf der Darstellung zu Charles Darwins evolutionärem Baum des Lebens und jener Abstammungslehre, die vielfach als narzissti-sche Kränkung empfunden wird. Den klassischen Konzepten von Mensch und Tier folgt mit J. v. Uexküll im 20. Jhdt. die Darstellung der als Subjekt aktiv ihre Umwelt gestalten-den Lebewesen. In der Suche nach dem Unterschied von Mensch und Tier widerspiegelt sich die Leib-Seele-Debatte, die nun als Diskussion um Funktionalität von Gehirn versus Erkenntnis als Vollzug zwischen Natur- und Geisteswissenschaften aufflammt. Der Geist der Tiere und damit verbunden ihre Empfindungsfähigkeit stehen vor allem im Zentrum der Forschung von Ethologen und Kognitionsbiologen. Das biologische Naheverhältnis zeigt sich auch in Mensch und Tier gemeinsamen Verhaltensweisen. In „Durchleuchtung“ von Moralkonzepten, die dem Tier einen moralischen Status zubilli-gen könnten, ist es Ursula Wolfs Konzept des generalisierten Mitleids, welches formal wohl keinen absoluten moralischen Standpunkt anbieten kann, aber ohne metaphysische Annahmen treffen zu müssen inhaltlich die Leidensfähigkeit von Tieren als moralrelevant begründet. Die graduelle Differenz aus der Evolution zwischen Mensch und Tier gibt dem Tier einen Platz unter den Menschen. Zum qualitativen Unterschied wird sie dann, wenn es um das Wissen eigenen Wissens geht, um das Erkennen von Bedürfnissen Andere und Verantwortlichkeit für das eigene Handeln Der Mensch ist fähig, moralische Urteile zu treffen, ist fähig, zwischen „gut und böse“ zu unterscheiden. Er weiß um das Gute und ist frei, sich dafür entscheiden zu können. In die-sem Wissen und dieser Freiheit ist der Mensch aufgefordert, als sittliches Wesen seinen Artegoismus zu überwinden und Tieren einen Platz in der moralischen Gemeinschaft zu-zugestehen. Eine dynamische Betrachtung der seit Darwin aufgebrochenen Grenzen zwi-schen Tier und Mensch ist nun auch in der Ethik vermehrt gefordert. Tierethik ist die Wei-chenstelle für die Art der Begründung von Sittlichkeit überhaupt