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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
661

Causes and Consequences of Fission-Fusion Dynamics in Female Northern Long-Eared Bats, Myotis septentrionalis

Patriquin, Krista 23 May 2012 (has links)
Individual costs and benefits of living in groups vary with group size, stability, and composition. Investigations of these features of group living have lead to the recognition of a variety of social structures. Although many studies have examined social structure in animals with long-term, stable groups, little is known about groups with highly variable group size and composition, such as fission-fusion dynamics. In this thesis I examined the causes and consequences of fission-fusion dynamics by exploring the socioecology of female northern long-eared bats, Myotis septentrionalis. Like many temperate bats, female northern long-eared bats show natal philopatry to summer areas. During this time, they live in groups with fission-fusion dynamics as individuals move among a network of roosts and roost-groups. To examine the causes of fission-fusion dynamics, I examined why females switch roosts. To address the consequences of these dynamics, I asked whether females could form stable relationships, and what factors might explain these relationships. I was able to identify the possible causes and consequences of fission-fusion dynamics that had not yet been explored in bats. I demonstrated that fission-fusion dynamics may be explained, at least in part, by changes in ambient conditions that prompt frequent roost-switching. Despite the highly dynamic nature of these groups, females formed long-term social relationships that were based in part on age and genetic relatedness. These findings have potential consequences for the evolution of social behaviour within groups, such as cooperation and nepotism. My work also raised several questions that require further examination to fully understand the evolution of fission-fusion dynamics. For example, the question remains whether species or sympatric groups of conspecifics with different degrees of roost-switching show the same social structure. By answering these questions, we can gain a better understanding of the causes and consequences of fission-fusion dynamics across species of bats. Once this is achieved, we can then look for parallels with other taxa to answer questions about the evolution of these dynamic systems.
662

Topics in Association Rules

Shaikh, Mateen 21 June 2013 (has links)
Association rules are a useful concept in data mining with the goal of summa- rizing the strong patterns that exist in data. We have identified several issues in mining association rules and addressed them in three main areas. The first area we explore is standardized interestingness measures. Different interestingness measures exist on different ranges, and interpreting them can be subtly problematic. We standardize several interestingness measures and show how these are useful to consider in association rule mining in three examples. A second area we address is incomplete transactions. By applying statistical methods in new ways to association rules, we provide a more comprehensive means of analyzing incomplete transactions. We also describe how to find families of distributions for interestingness measure values when transactions are incomplete. Finally, we address the common result of mining: a plethora of association rules. Unlike methods which attempt to reduce the number of resulting rules, we harness this large quantity to find a higher-level set of patterns. / NSERC Discovery Grant and OMRI Early Researcher Award
663

Reaction of North American Oats (Avena sativa L.) to Crown Rust

Lange, Carol Jeannine 1986- 14 March 2013 (has links)
Crown rust, caused by the fungus Puccinia coronata, is a severe disease negatively impacting seed quality and yield in oat (Avena sativa). Host genetic resistance is the primary means for controlling this disease. The most extensive oat map contains nearly 2,500 genetic markers, many of which are restriction and amplified fragment length polymorphic (RFLP or AFLP) markers. However, the use of more abundant single nucleotide polymorphic (SNP) markers combined with diversity arrays technology (DArT) would be more advantageous for marker assisted breeding (MAB) and genome wide selection (GWS) applications due to the availability of high density genotyping technologies. The purpose of using this technology is to improve the competitiveness of oat by producing varieties with durable resistance to crown rust and desirable traits that will benefit oat growers in the U.S. Panels of winter and spring oat were evaluated for resistance to crown rust in four field environments in Texas, Louisiana, Minnesota, and North Dakota during a two-year study in 2010 and 2011. Plants representing 702 elite lines of oat were phenotyped for crown rust resistance and found to have highly diverse responses. The winter oat lines demonstrated the best crown rust resistance and are expected to yield the most QTL to be used in developing durable crown rust resistance. Heritability of crown rust resistance in this study ranged from 0.88 to 0.90 in spring and winter oats, respectively. Crown rust measurements were also found to be repeatable. Repeatability ranged from 0.56 to 0.88 at Castroville, TX in 2011 and 2010, respectively in spring oats and from 0.79 at St. Paul, MN in 2011 to 0.96 at Castroville, TX in 2010 in winter oats. Oat lines contributed by states along the Puccinia pathway in Texas, Louisiana, Minnesota, North Dakota, and Wisconsin on average exhibited the best crown rust resistance as compared to other areas in the country where spring and winter oat are grown. GGE biplot analysis indicated that Castroville, TX was the most representative and most ideal testing location. The above results are expected to increase knowledge of the genetic diversity of the oat germplasm, yield comprehensive genotyping and phenotyping information for North American oat breeding programs, and to promote further use of GWS and MAB for key traits regarding disease resistance in oat. Future work is to conclude the association mapping process by completing genotypic analysis.
664

The role of dopamine-related genes in autism spectrum disorders: Evidence for specific genes and risk for ASD in families with affected males

Hettinger, Joseph Alan 25 March 2009 (has links)
Individuals with autism spectrum disorders (ASDs) are impaired in cognitive processes and emotional regulation, and exhibit stereotyped behaviours. Dopamine (DA) modulates executive functions, learning, memory, emotional processing and social cognition; all of which are impaired in individuals with ASDs. Because DA modulates a number of processes that are impaired in individuals with ASDs, genes in the dopaminergic pathway are good candidates for genes influencing autistic behaviours. As our previous findings suggested a role for a dopamine-related gene in families with only affected males, this thesis describes a comprehensive study of five genes affecting DA synthesis, levels and function in mothers and affected males with ASDs in an initial TEST cohort of 112 male-only affected sib-pair families as well as a replication study in three additional male-only family cohorts. I genotyped three to five polymorphisms in the TH, SLC6A3, DRD1, DRD2 and PPP1R1B genes and performed population-based single marker case-control comparisons, family-based association tests, quantitative transmission disequilibrium tests as well as haplotype-based analyses and tests for gene-gene interactions. I found evidence for association of the DRD1 (P=0.0027-0.040), DRD2 (P=0.0002-0.007) and PPP1R1B (P=0.00042-0.001) genes with autism in affected males from the TEST cohort. Evidence for DA-related gene interactions were found between polymorphisms in DRD1, DRD2 and PPP1R1B (P=0.0094-0.012) in affected males relative to a comparison group. Furthermore, I found that polymorphisms in the TH and DRD1 genes were associated with the risk for mothers having sons with ASD in the TEST families (P=0.007-0.025) and putative risk alleles in DRD1 and DRD2 were preferentially transmitted from mothers (P=0.016) and fathers (P=0.023) respectively, to affected children. All findings remained significant following corrections for multiple testing. The TEST cohort findings were not replicated in other family cohorts. However, an examination of dysmorphology data for the different family sets revealed phenotypic differences and thus, genetic differences are to be expected. In summary, I found evidence for a contribution of DA-related genes in a specific family cohort with ASDs. Additional functional and phenotypic studies will enable a better understanding of the contributions and implications of these findings to our understanding of autism. / Thesis (Ph.D, Physiology) -- Queen's University, 2009-03-18 13:58:12.223
665

Cultural Identity and Transnational Networks in a Chinese Diaspora Society in Sibu, Sarawak, Malaysia

Hsu, Yu-tsuen Unknown Date
No description available.
666

Patterns of Genomic Variation and Whole Genome Association Studies of Economically Important Traits in Cattle

Li, Honghao Unknown Date
No description available.
667

The amateur draft, competitive balance, and tanking in the National Basketball Association

Soebbing, Brian Philip Unknown Date
No description available.
668

The scheduled and non-scheduled international air transport service : a need for a definition / The scheduled and non-scheduled air transport services.

Robert-Andino, Luis F. January 1972 (has links)
No description available.
669

La liberté d'association au Canada et la liberté syndicale à l'OIT : synonymes?

Choko, Maude. January 2008 (has links)
On June 8, 2007, the Supreme Court of Canada [SCC] overruled its jurisprudence of the past twenty years on freedom of association. The majority of the judges agreed that section 2d) of the Canadian Charter of Rights and Freedoms protects the right to the process to collective bargaining. In doing so, the SCC rejected the ratio of the majority enunciated in the 1987 trilogy and, at last, gave place to international labour law, in particular to freedom of association principles elaborated by the International Labour Organization's supervisory bodies. The analysis of these principles, focused on three related rights, i.e. the right to collective bargaining, the right to strike and the right not to associate, allows the author to conclude that for the first time, Canada is showing greater respect for its international obligations. What the SCC will decide for the right to strike remains to be seen.
670

Validating cohesion metrics by mining open source software data with association rules

Singh, Pariksha January 2008 (has links)
Dissertation submitted for the fulfillment of the requirement for the degree of Masters in Information Technology, Department of Information Technology, Faculty of Accounting and Informatics, Durban University of Technology, 2008. / Competitive pressure on the software industry encourages organizations to examine the effectiveness of their software development and evolutionary processes. Therefore it is important that software is measured in order to improve the quality. The question is not whether we should measure software but how it should be measured. Software measurement has been in existence for over three decades and it is still in the process of becoming a mature science. The many influences of new software development technologies have led to a diverse growth in software measurement technologies which have resulted in various definitions and validation techniques. An important aspect of software measurement is the measurement of the design, which nowadays often means the measurement of object oriented design. Chidamer and Kemerer (1994) designed a metric suite for object oriented design, which has provided a new foundation for metrics and acts as a starting point for further development of the software measurement science. This study documents theoretical object oriented cohesion metrics and calculates those metrics for classes extracted from a sample of open source software packages. For each open source software package, the following data is recorded: software size, age, domain, number of developers, number of bugs, support requests, feature requests, etc. The study then tests by means of association rules which theoretical cohesion metrics are validated hypothesis: that older software is more cohesive than younger software, bigger packages is less cohesive than smaller packages, and the smaller the software program the more maintainable it is. This study attempts to validate existing theoretical object oriented cohesion metrics by mining open source software data with association rules.

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