Sökning: "tree variation"

Visar resultat 1 - 5 av 124 avhandlingar innehållade orden tree variation.

1. 1. Genetic variation in structured populations

   Författare :Marina Rafajlovic; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; genetic variation; varying population size; effective population size; mutation; recombination; migration; multiple paternity; geographic structure; tests of neutrality; gene tree; species tree;

   Sammanfattning : It is widely acknowledged that the process of speciation in the presence of gene flow between different ecotypes is common in nature. However, the mechanisms underlying speciation are not understood. LÄS MER

3. 2. Tracing selection and adaptation along an environmental gradient in Populus tremula

   Författare :David Hall; Pär Ingvarsson; Thomas Bataillon; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Local adaptation; Selection; genetic differentiation; QST; FST; Association study; frequency spectra; recurrent hitchhiking; selective sweep; Tree; Populus; natural selection; quantitative genetics; Terrestrial ecology; Terrestrisk ekologi; Population Biology; populationsbiologi; genetik; Genetics;

   Sammanfattning : The distribution of the expressed genotype is moved around in the population over time byevolution. Natural selection is one of the forces that act on the phenotype to change the patterns ofnucleotide variation underlying those distributions. LÄS MER

4. 3. Game of crops : genetic composition and adaptation of seed orchard crops

   Författare :Alisa Heuchel; Xiao-Ru Wang; David Hall; Ulfstand Wennström; Jaroslaw Burczyk; Umeå universitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; seed orchards; GBS; linear deployment; tree improvement; genetic diversity; adapation; topgrafting; Scots pine; Norway spruce; improved reforestation material; field performance; flowering stimulation; fertility variation; Genetics; genetik; environmental science; miljövetenskap;

   Sammanfattning : Orchard populations are artificial and intensively managed populations of elite, best-performing trees that are established for mass production of genetically improved seeds. Seed orchards connect cycles of selection, breeding, and testing of plus-trees with the deployment of the improved seeds at the operational plantations. LÄS MER

5. 4. Modelling Phone-Level Pronunciation in Discourse Context

   Författare :Per-Anders Jande; Rolf Carlson; Merle Horne; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pronunciation modelling; Pronunciation variation; Discourse-context; Phone-level variation; Central standard Swedish; Spoken language annotation; Data-driven methods; Machine learning; Decision trees; Pronunciation lexicon development; Machine-readable lexicon; Phonology; Discourse; Lexicon; Language technology; Språkteknologi;

   Sammanfattning : Analytic knowledge about the systematic variation in a language has an important place in the description of the language. Such knowledge is interesting e.g. in the language teaching domain, as a background for various types of linguistic studies, and in the development of more dynamic speech technology applications. LÄS MER

7. 5. Behavior Representation by Growing a Learning Tree

   Författare :Tomas Landelius; Hans Knutsson; Linköpings universitet; []
   Nyckelord :TECHNOLOGY; TEKNIKVETENSKAP;

   Sammanfattning : The work presented in this thesis is based on the basic idea of learning by reinforcement, within the theory of behaviorism. The reason for this choice is the generality of such an approach, especially that the reinforcement learning paradigm allows systems to be designed which can improve their behavior beyond that of their teacher. LÄS MER