Physical Sciences and Mathematics Commons^™

Rational Functions Of Degree Five That Permute The Projective Line Over A Finite Field, Christopher Sze

USF Tampa Graduate Theses and Dissertations

Rational functions over a finite field Fq induce mappings from the projective line P1(Fq) to itself. Rational functions that permute the projective line are called permutation rational functions (PRs). The notion of permutation rational functions is a natural extension of the permutation polynomials which have been studied for over a century. Recently, PRs of degrees up to four have been determined. This dissertation is a project aimed at determining PRs of degree five.

Rational functions of degree five (excluding those that are equivalent to polynomials) are divided into five cases according to the factorization of their denominators. Our main results …

Prepare For, Respond To, Recover, And Learn From Disasters: Using Data-Driven Methods To Model And Understand Disaster Resilience, Jinwen Xu

USF Tampa Graduate Theses and Dissertations

Community resilience reflects the ability of human communities to prepare for, respond to, recover, and learn from disastrous events. Community resilience carries different meanings in different phases of disaster management (i.e., preparedness, response, recovery, and mitigation). With the emergence of new geospatial data sources, human activities now can be captured through social media, mobile signals, and nighttime illuminations, which makes it possible to describe the conditions among various communities before, during, and after disasters. Therefore, this dissertation explored the use of different types of geospatial data sources (social media, nighttime light remote sensing, land-use data, and census survey data) during …

Ureca – The Research Ethics And Data Protection Online Review Platform Used By The University Of Malta, Joel Azzopardi

The Journal of Electronic Theses and Dissertations

Nowadays, research ethics and data protection are given very high importance, and research organizations, including universities, need to safeguard their level of professionalism and integrity by providing the necessary guidelines. Moreover, they need to ensure that these guidelines are being adhered to by their affiliated researchers, including students. This is needed for protection of the research subjects, researchers, and the organization (university) itself. However, care must be taken so that the research ethics review process is streamlined as much as possible to minimize bureaucracy, as such guidelines would then be viewed as a research barrier. This study describes URECA, the …

Screening Genes For Association With Loci For Nitrogen-Use Efficiency In Perennial Ryegrass By PyrosequencingTm, O. Dolstra, D. Dees, J. -D. Driesprong, E. N. Van Loo

IGC Proceedings (1977-2023)

The application of marker-assisted selection to improve quantitative traits in perennial ryegrass (Lolium perenne) is cumbersome. It requires a priori knowledge on the association of markers and genes. The knowledge on the chromosomal location of major genes for quantitative traits as well as on gene sequences is rapidly growing. However, determination of the genetic constitution of parents prior to their use in breeding still is impractical. More realistic is to collect association data along with the testing activities needed for breeding new varieties. This study uses changes in allele frequency due to selection as a criterion for gene-trait …

Gene-Associated Single Nucleotide Polymorphism (Snp) Discovery In Perennial Ryegrass (Lolium Perenne L.), J. W. Forster, N. O. I. Cogan, A. C. Vecchies, R. C. Ponting, M. C. Drayton, J. George, J. L. Dumsday, G. C. Spangenberg, K. F. Smith

IGC Proceedings (1977-2023)

Perennial ryegrass (Lolium perenne L.) is the most important grass species for temperate pasture systems world-wide. Varietal improvement programs for this obligate outbreeding species are based on polycrossing of multiple parents to produce heterogeneous synthetic populations. The complexity of breeding systems creates challenges and opportunities for molecular marker technology development and implementation. Previous research has led to: the generation of a comprehensive suite of simple sequence repeat (SSR) markers, reference genetic map construction, comparative genetic studies, QTL identification, and population structure analysis. Emphasis has now shifted from the use of anonymous genetic markers linked to trait-specific genes to the …

Isolation Of Candidate Genes Involved In Cold Temperatures Response In Festuca Pratensis Huds., Using Suppression Subtractive Hybridisation And Microarray Approaches, H. Rudi, V. Alm, L. Opseth, A. Larsen, O. A. Rognli

IGC Proceedings (1977-2023)

The objective of this work was to isolate candidate genes which are differentially expressed following cold-acclimation and develop SNPs to test for associations between candidate genes and frost tolerance. The ability to develop sufficient levels of tolerance against freezing temperatures through cold-acclimation (hardening) is crucial for survival of grasses and winter cereals in temperate climate. Meadow fescue (Festauca pratensis Huds.) is one of the most important forage grass species in Northern Europe. The preference of Festuca instead of Lolium in Norway is due to its superior combination of winter hardiness and forage quality.

Positive Effect Of Increased Aflp Diversity Among Parental Plants On Yield Of Polycross Progenies In Perennial Ryegrass (Lolium Perenne L.), R. Kölliker, B. Boller, F. Widmer

IGC Proceedings (1977-2023)

In outbreeding forage crops such as perennial ryegrass (Lolium perenne L.), genetic diversity among parental plants may greatly influence the success of a cultivar through mechanisms such as heterosis and inbreeding depression. The aim of this study was to evaluate the use of amplified fragment length polymorphism (AFLP) markers to select polycross parents with contrasting levels of genetic diversity and to analyse genetic diversity and agronomic performance of first and second generation synthetic progenies (Syn1, Syn2).

Ryegrass Astra: A Web-Based Resource For Lolium Est Analysis, G. C. Spangenberg, T. Sawbridge, E. K. Ong, C. G. Love, T. A. Erwin, E. G. Logan, D. Edwards

IGC Proceedings (1977-2023)

Perennial ryegrass (Lolium perenne L.) is a major grass species of temperate pastoral agriculture.

Genomic Constitution Of Festulolium Varieties, D. Kopecky, V. Cernoch, R. Capka, J. Dolezel

IGC Proceedings (1977-2023)

Hybrids between species of ryegrass (Lolium) and fescue (Festuca) combine useful agronomical characteristics such as rapid establishment from seed and fodder quality from ryegrass and tolerance against abiotic and biotic stressses from fescue. The superior potential of hybrids has stimulated breeding programs generating so called Festulolium varieties. While the varieties have been evaluated extensively for their agronomic characteristics, little information is publicly available on their genomic constitution. The aim of our study was to analyse genomic constitution of a representative set of commercially available European Festulolium cultivars. To do this, we have employed genomic in situ …

Genetic Changes Over Breeding Generations Of Festulolium, M. Ghesquière, P. Barre, L. Barrot

IGC Proceedings (1977-2023)

Festulolium hybrids are a valuable breeding source for tolerance to abiotic stress and to make grass more persistent under drought and in cold environments. In 2004, the EU Commission enlarged the definition of Festulolium which may now include all hybrids between Lolium sp. and Festuca sp. and not only those between L. multiflorum and F. pratensis. We here report allele frequencies at two unlinked PCR-based marker loci in populations derived from tetraploid (2n=4x=28) L. multiflorum x F. glaucescens hybrids where breeding history enables us to test the effects of selection vs that of genetic drift.

Development And Testing Of Novel Chloroplast Markers For Perennial Ryegrass From De Novo Sequencing And In Silico Sequences, S. Mcgrath, T. R. Hodkinson, S. Barth

IGC Proceedings (1977-2023)

Chloroplast DNA is uniparentally inherited and non-recombinant in Lolium perenne. These properties make the chloroplast genome a useful tool for studying inter- and intra- specific relationships. Previous genetic studies on L. perenne have used chloroplast sequence data. However, the relative lack of variation in the chloroplast genome limits its usefulness for analysis at the single individual level within a species. However, chloroplast SSR markers have recently been shown to have high levels of polymorphism (Provan et al., 2004). This is the first study to design and employ such markers for L. perenne. The objectives of this study …

Genetic Analysis Of The Interaction Between Perennial Ryegrass And The Fungal Endophyte Neotyphodium Lolii, E. Van Zijll De Jong, A. C. Vecchies, M. P. Dobrowolski, N. O. I. Cogan, K. F. Smith, G. C. Spangenberg, J. W. Forster

IGC Proceedings (1977-2023)

The fungal endophyte Neotyphodium lolii is widely distributed in perennial ryegrass pastures, especially in Australia and New Zealand. The presence of the endophyte is associated with improved tolerance to water and nutrient stress and resistance to insect pests, but is accompanied by reduced herbivore feeding. The molecular mechanisms responsible for these endophyte-related traits are in general poorly understood. Comparisons of different grass-endophyte associations show that endophyte-related traits are affected by both endophyte and host genotype, and environmental interactions.

Microarray-Based Transcriptome Analysis Of The Interaction Between Perrenial Ryegrass (Lolium Perenne) And The Fungal Endophyte Neotyphodium Lolii, S. Felitti, P. Tian, T. Webster, D. Edwards, G. C. Spangenberg

IGC Proceedings (1977-2023)

Neotyphodium lolii, Neotyphodium coenophialum and Epichloë festucae are common symbiotic fungal endophytes of the temperate pasture grasses perennial ryegrass (Lolium perenne), tall fescue (Festuca arundinacea) and red fescue (Festuca rubra), respectively. A genomic resource of 13,964 expressed sequence tags (ESTs), representing 7,585 unique endophyte genes, has been established for Neotyphodium and Epichloë fungal endophytes.