Genetic variation of temperature-regulated curd induction in cauliflower: elucidation of floral transition by genome-wide association mapping and gene expression analysis

Cauliflower (Brassica oleracea var. botrytis) is a vernalization-responsive crop. High ambient temperatures delay harvest time. The elucidation of the genetic regulation of floral transition is highly interesting for a precise harvest scheduling and to ensure stable market supply. This study aims at genetic dissection of temperature-dependent curd induction in cauliflower by genome-wide association studies and gene expression analysis. To assess temperature dependent curd induction, two greenhouse trials under distinct temperature regimes were conducted on a diversity panel consisting of 111 cauliflower commercial parent lines, genotyped with 14,385 SNPs. Broad phenotypic variation and high heritability (0.93) were observed for temperature-related curd induction within the cauliflower population. GWA mapping identified a total of 18 QTL localized on chromosomes O1, O2, O3, O4, O6, O8, and O9 for curding time under two distinct temperature regimes. Among those, several QTL are localized within regions of promising candidate flowering genes. Inferring population structure and genetic relatedness among the diversity set assigned three main genetic clusters. Linkage disequilibrium (LD) patterns estimated global LD extent of r(2) = 0.06 and a maximum physical distance of 400 kb for genetic linkage. Transcriptional profiling of flowering genes FLOWERING LOCUS C (BoFLC) and VERNALIZATION 2 (BoVRN2) was performed, showing increased expression levels of BoVRN2 in genotypes with faster curding. However, functional relevance of BoVRN2 and BoFLC2 could not consistently be supported, which probably suggests to act facultative and/or might evidence for BoVRN2/BoFLC-independent mechanisms in temperature regulated floral transition in cauliflower. Genetic insights in temperature-regulated curd induction can underpin genetically informed phenology models and benefit molecular breeding strategies toward the development of thermo-tolerant cultivars.

Engineering the transition from non-living to living matter

Re-creating and understanding the origin of life represents one of the major challenges facing the scientific community. We will never know exactly how life started on planet Earth, however, we can reconstruct the most likely chemical pathways that could have contributed to the formation of the first living systems. Traditionally, prebiotic chemistry has investigated the formation of modern life’s precursors and their self-organisation under very specific conditions thought to be ‘plausible’. So far, this approach has failed to produce a living system from the bottom-up. In the work presented herein, two different approaches are employed to explore the transition from inanimate to living matter. The development of microfluidic technology during the last decades has changed the way traditional chemical and biological experiments are performed. Microfluidics allows the handling of low volumes of reagents with very precise control. The use of micro-droplets generated within microfluidic devices is of particular interest to the field of Origins of Life and Artificial Life. Whilst many efforts have been made aiming to construct cell-like compartments from modern biological constituents, these are usually very difficult to handle. However, microdroplets can be easily generated and manipulated at kHz rates, making it suitable for high-throughput experimentation and analysis of compartmentalised chemical reactions. Therefore, we decided to develop a microfluidic device capable of manipulating microdroplets in such a way that they could be efficiently mixed, split and sorted within iterative cycles. Since no microfluidic technology had been developed before in the Cronin Group, the first chapter of this thesis describes the soft lithographic methods and techniques developed to fabricate microfluidic devices. Also, special attention is placed on the generation of water-in-oil microdroplets, and the subsequent modules required for the manipulation of the droplets such as: droplet fusers, splitters, sorters and single/multi-layer micromechanical valves. Whilst the first part of this thesis describes the development of a microfluidic platform to assist chemical evolution, finding a compatible set of chemical building blocks capable of reacting to form complex molecules with endowed replicating or catalytic activity was challenging. Abstract 10 Hence, the second part of this thesis focuses on potential chemistry that will ultimately possess the properties mentioned above. A special focus is placed on the formation of peptide bonds from unactivated amino acids, despite being one of the greatest challenges in prebiotic chemistry. As opposed to classic prebiotic experiments, in which a specific set of conditions is studied to fit a particular hypothesis, we took a different approach: we explored the effects of several parameters at once on a model polymerisation reaction, without constraints on hypotheses on the nature of optimum conditions or plausibility. This was facilitated by development of a new high-throughput automated platform, allowing the exploration of a much larger number of parameters. This led us to discover that peptide bond formation is less challenging than previously imagined. Having established the right set of conditions under which peptide bond formation was enhanced, we then explored the co-oligomerisation between different amino acids, aiming for the formation of heteropeptides with different structure or function. Finally, we studied the effect of various environmental conditions (rate of evaporation, presence of salts or minerals) in the final product distribution of our oligomeric products.

Flower abscission and fruit set on table grapes (Vitis vinifera L.): unraveling physiological and molecular mechanisms

Doutoramento em Engenharia Agronómica - Instituto Superior de Agronomia - UL

Spatial aid spillovers during transition

We investigate whether development aid stimulates growth in transition economies, paying particular attention to the possibility of spatial spillovers arising from aid. We find that common borders and a shared historical and political heritage result in a complex set of associations between aid and growth. Aid has a positive impact on growth in the recipient country. However, the impact of aid also spills over to affect other nations. Aid appears to create positive spillovers through improved total factor productivity and possibly currency appreciation. At the same time, aid depletes human capital through emigration and it particularly adversely affects democracy and governance quality in other transition economies. On balance, aid generates net adverse growth spillovers in transition economies.

Transition: improved literacy outcomes research study

This paper reports on the Transition: Improved Literacy Outcomes Research Study established by the Department of Education and Training (DET). The purpose of the study was to identify the most useful and usable data for educators to access in order to ensure that student literacy learning is maximised during the transition from Primary to Secondary school.1. The research followed a mixed-methods approach, combining a statistically defensible sample of schools selected to represent school types (primary, secondary, combined), locations (rural, regional, urban) and all regions with a survey and follow- up interviews.2. The results are presented as a mixture of statistics, case studies and discussion. The case studies were developed from both survey data and interview data.3. Leaders and teachers overwhelmingly valued teacher judgement (through AusVELS) as the most useful data in understanding students’ strengths and weaknesses, followed by On-Demand testing.4. NAPLAN results were frequently transferred between schools, but were found to be less useful than other data by teachers.5. School leaders and teachers are currently using data for ability streaming, or for tailoring curriculum for individual student needs. A number of schools use the Literacy data for achieving a balance of student abilities within classes.6. Support for access to, and use of, data is mainly manual, with some use of spreadsheets.7. As the number of feeder Primary schools to a single Secondary school increases, data management becomes a much larger burden on the Secondary staff concerned.8. In Secondary schools, there was a clear demand for Literacy data, but these data were not always those that were being provided by their feeder Priamary schools. This mis-match appears to lead to some frustration among Literacy transition staff at both levels of schooling.9. A gap that needs filling is around the nature of the pedagogies at the two school levels. Not knowing, or misunderstanding, the approaches and needs of each level of schooling leads to the passing on of irrelevant Literacy data in some instances.10. The need for a common template for transition data was expressed by many Transition staff, both Primary and Secondary. In some instances the secondary school had set up a local template for this11. It would be advantageous for data to be directly up-loaded or transferred into a system via electronic tools already in use, such as an Excel spreadsheet.12. We would recommend that the capacity to provide some visualisation of data, and the compilation of internal Literacy data such as teacher judgements and AusVELS levels, or additional testing carried out by the school.13. Student background data was seen by many Secondary transition staff as being equally as valuable as more formal Literacy data for determining student needs.

Hegemonic masculinity in transition

Comprised of a creative artefact and an exegesis, the research examines how destabilisation and critique of patriarchal hierarchies in the post-World War II era has challenged and transformed societal and personal relationships. The creative artefact is a novel set in Australia. The exegesis is focussed on the response to changing masculinities in film, primarily Westerns.

An application of fractal image-set coding in facial recognition

Faces are complex patterns that often differ in only subtle ways. Face recognition algorithms have difficulty in coping with differences in lighting, cameras, pose, expression, etc. We propose a novel approach for facial recognition based on a new feature extraction method called fractal image-set encoding. This feature extraction method is a specialized fractal image coding technique that makes fractal codes more suitable for object and face recognition. A fractal code of a gray-scale image can be divided in two parts – geometrical parameters and luminance parameters. We show that fractal codes for an image are not unique and that we can change the set of fractal parameters without significant change in the quality of the reconstructed image. Fractal image-set coding keeps geometrical parameters the same for all images in the database. Differences between images are captured in the non-geometrical or luminance parameters – which are faster to compute. Results on a subset of the XM2VTS database are presented.