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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.
1

Genes Encoding Flower- and Root-Specific Functions Are More Resistant to Fractionation Than Globally Expressed Genes in Brassica rapa

Kolkailah, Naiyerah F 01 June 2016 (has links) (PDF)
Like many angiosperms, Brassica rapa underwent several rounds of whole genome duplication during its evolutionary history. Brassica rapa is particularly valuable for studying genome evolution because it also experienced whole genome triplication shortly after it diverged from the common ancestor it shares with Arabidopsis thaliana about 17-20 million years ago. While many B. rapa genes appear resistant to paralog retention, close to 50% of B. rapa genes have retained multiple, paralogous loci for millions of years and appear to be multi-copy tolerant. Based on previous studies, gene function may contribute to the selective pressure driving certain genes back to singleton status. It is suspected that other factors, such as gene expression patterns, also play a role in determining the fate of genes following whole genome triplication. Published RNA-seq data was used to determine if gene expression patterns influence the retention of extra gene copies. It is hypothesized that retention of genes in duplicate and triplicate is more likely if those genes are expressed in a tissue-specific manner, as opposed to being expressed globally across all tissues. This study shows that genes expressed specifically in flowers and roots in B. rapa are more resistant to fractionation than globally expressed genes following whole genome triplication. In particular, there appears to have been selection on genes expressed specifically in flower tissues to retain higher copy numbers and for all three copies to exhibit the same flower-specific expression pattern. Future research to determine if these observations in Brassica rapa are consistent with other angiosperms that have undergone recent whole genome duplication would confirm that retention of flower-specific-expressed genes is a general feature in plant genome evolution and not specific to B. rapa.
2

Architecture matérielle et flot de programmation associé pour la conception de systèmes numériques tolérants aux fautes / Hardware architecture and associated programming flow for the design of digital fault-tolerant systems

Peyret, Thomas 02 December 2014 (has links)
Que ce soit dans l’automobile avec des contraintes thermiques ou dans l’aérospatial et lenucléaire soumis à des rayonnements ionisants, l’environnement entraîne l’apparition de fautesdans les systèmes électroniques. Ces fautes peuvent être transitoires ou permanentes et vontinduire des résultats erronés inacceptables dans certains contextes applicatifs. L’utilisation decomposants dits « rad-hard » est parfois compromise par leurs coûts élevés ou les difficultésd’approvisionnement liés aux règles d’exportation.Cette thèse propose une approche conjointe matérielle et logicielle indépendante de la technologied’intégration permettant d’utiliser des composants numériques programmables dans desenvironnements susceptibles de générer des fautes. Notre proposition comporte la définitiond’une Architecture Reconfigurable à Gros Grains (CGRA) capable d’exécuter des codes applicatifscomplets mais aussi l’ensemble des mécanismes matériels et logiciels permettant de rendrecette architecture tolérante aux fautes. Ce résultat est obtenu par l’association de redondance etde reconfiguration dynamique du CGRA en s’appuyant sur une banque de configurations généréepar une chaîne de programmation complète. Cette chaîne outillée repose sur un flot permettantde porter un code sous forme de Control and Data Flow Graph (CDFG) sur l’architecture enobtenant un grand nombre de configurations différentes et qui permet d’exploiter au mieux lepotentiel de l’architecture.Les travaux, qui ont été validés aux travers d’expériences sur des applications du domaine dutraitement du signal et de l’image, ont fait l’objet de publications en conférences internationaleset de dépôts de brevets. / Whether in automotive with heat stress or in aerospace and nuclear field subjected to cosmic,neutron and gamma radiation, the environment can lead to the development of faults in electronicsystems. These faults, which can be transient or permanent, will lead to erroneous results thatare unacceptable in some application contexts. The use of so-called rad-hard components issometimes compromised due to their high costs and supply problems associated with exportrules.This thesis proposes a joint hardware and software approach independent of integrationtechnology for using digital programmable devices in environments that generate faults. Ourapproach includes the definition of a Coarse Grained Reconfigurable Architecture (CGRA) ableto execute entire application code but also all the hardware and software mechanisms to make ittolerant to transient and permanent faults. This is achieved by the combination of redundancyand dynamic reconfiguration of the CGRA based on a library of configurations generated by acomplete conception flow. This implemented flow relies on a flow to map a code represented as aControl and Data Flow Graph (CDFG) on the CGRA architecture by obtaining directly a largenumber of different configurations and allows to exploit the full potential of architecture.This work, which has been validated through experiments with applications in the field ofsignal and image processing, has been the subject of two publications in international conferencesand of two patents.
3

Reduplikuotiniai lietuvių kalbos žodžiai / Reduplicative words in lithuanian language

Uselytė, Jurgita 22 June 2005 (has links)
Reduplication is a morphological process in which the root or stem of a word, or part of it, is repeated. Reduplication is used both inflectionally to convey a grammatical function, such as plurality, intensification, etc., and derivationally to create new words. It is found in many languages, though its importance and productivity varies. Reduplication is often described phonologically in two different ways: (1) as reduplicated segments (i.e. sequences of consonants/vowels) or (2) as reduplicated prosodic units (i.e. syllables or morae). In addition to phonological description, reduplication often needs to be described morphologically as a reduplication of linguistic constituents (i.e. words, stems, roots). As a result, reduplication is interesting theoretically as it involves the interface between phonology and morphology. Reduplication often involves copying only once. However, in some languages, reduplication can happen more than once (and thus a duple is not created). Triplication is the term for copying three times (i.e. in Lithuanian language av av av; dū dū dū; bum bum bum; plest plest plest). Full reduplication involves a reduplication of the entire word (i.e. nunù, riri, rururù, ka-ka). In Lithuanian there are two types of fullreduplication: word reduplication (i.e. baubau, bė́bė; bobõ; būbū), syllable reduplication (i.e. girkšt girkšt, jo jo, kepu kepu). Partial reduplication involves a reduplication of only part of the word, eg. papákšt (veiksmažodis pakštelėti)... [to full text]

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