Sirvi Kuupäev , alustades "2010-05-11" järgi

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Variation in vowel quality as a feature of Estonian quantity
(2010-05-11) Lippus, Pärtel
Systematic studies on the subfamily Sterrhinae (Lepidoptera: Geometridae)
(2010-05-11T06:48:44Z) Õunap, Erki
This thesis focuses on problems related to the systematics of the moth subfamily Sterrhinae, one of the largest subfamilies of ‘loopers’ (Geometridae). Molecular phylogenetic analysis proved that the European ‘blood-vein’ is a complex of two closely related species, namely Timandra griseata and T. comae. There was also some evidence that these species may occasionally hybridize. I showed that the small Palaearctic genus Lythria belongs in the Sterrhinae subfamily rather than the Larentiinae subfamily, which was the previously prevailing opinion. This result was confirmed both using molecular phylogenetic analysis and examination of morphological characteristics. Moreover, I showed that certain morphological characteristics related to the wing venation that had previously been thought to be critical in distinguishing between Sterrhinae and Larentiinae are in fact unsuitable for that purpose, as they occur in both groups. Lythria venustata, a species hitherto only recorded in Kazakhstan, was shown to differ considerably from all other representatives of the genus Lythria. The remaining four Lythria species formed two groups of sister taxa: the widely-distributed Eurasian species L. purpuraria was closely related to L. plumularia, which is an endemic of European High Alps; L. cruentaria, another widely-distributed Eurasian species, was closely related to L. sanguinaria, whose distribution is confined to the Iberian Peninsula and southern France. Using molecular phylogenetic analysis I divided the subfamily Sterrhinae into two lineages: one comprising the tribes Rhodostrophiini, Scopulini and Sterrhini; and the other comprising the tribes Cosymbiini, Timandrini, Rhodometrini and Lythriini. This division is in concordance with recent morpho-cladistic analysis.
Characterization of Myg1 gene and protein: expression patterns, subcellular localization, gene deficient mouse and functional polymorphisms in human
(2010-05-11T06:59:20Z) Philips, Mari-Anne
Myg1 is one of the most conserved genes that has been evolutionarily crucial to maintain from protozoans to humans. Despite that Myg1 has not been associated with any remarkable disease conditions or fundamental cellular processes. The main purpose of the current study was to characterize Myg1 (Melanocyte proliferating gene 1) gene and to generate relevant data about this novel gene and protein. In our study group, Myg1 was first identified as a most extensively up-regulated gene in the amygdaloid area of rats after cat odour-induced anxiety (Kõks et al, 2004). Studies linked to the current dissertation were designed to shed light on the function of the Myg1 gene that had previously been cited in only one scientific abstract (Smicun, 2000) describing Myg1 as a highly expressed gene in freely proliferating melanocytes and downregulated in malignant melanoma cells. In the current study we found that in adult tissues Myg1 mRNA expression is ubiquitous and homogeneous; in different embryonic phases Myg1 expression is characterized by a specific pattern and dynamic intensity, indicating developmental impact of Myg1. Myg1 localizes in the nucleus and mitochondria and we also demonstrated the existence of nuclear and mitochondrial targeting signals in the N-terminal region of human and mouse Myg1 proteins. We showed that Myg1 4Gln allele that has remarkable prevalence in the Nigerian population, disturbs mitochondrial entrance of Myg1. Because our subjects from the Estonian population were consistently homozygous for Myg1 4Arg allele, we can not confirm the relevance of Myg1 Arg4Gln, but our current results suggest that Myg1 has indispensable functions in the mitochondria. According to our studies it is most likely that Myg1 is involved in cellular pathways implicated in cellular stress, immune response, development and metabolism. Phenotyping of Myg1-deficient mice revealed that Myg1 (-/-) mice are vital, fertile and display no gross abnormalities. Myg1-deficiency caused moderate alterations in anxiety-related behaviour and stress-reactions in mice, but also remarkable reduction of sex-dependent behavioural differences. In our primary screen Myg1-deficient mice displayed no significant alterations in immune response or metabolic activity but several mild tendencies encourage us to study these functions further in Myg1 (-/-) mice. Both MYG1 promoter polymorphism -119C/G and Arg4Gln polymorphism in the mitochondrial signal of Myg1 have a functional impact on the regulation of the MYG1 gene. Our in vivo and in vitro promoter activity analysis together with association analysis confirms that -119C/G polymorphism influences MYG1 mRNA levels. Our results suggest that more active -119G is the risk-allele for the development of vitiligo and more specifically risk-allele for the maintenance of the active progression stage of the disease.
The commuting bounded approximation property of Banach spaces
(2010-05-11T10:00:56Z) Zolk, Indrek
Väitekiri on funktsionaalanalüüsi alane uurimus. Funktsionaalanalüüs on matemaatikaharu, mille alguseks loetakse Banachi 1932. aastal ilmunud monograafiat lineaarsete operaatorite teooriast. Aproksimatsiooniomaduste (edaspidi a.o.) vallas on teinud 1950. aastatel põhjalikku tööd Grothendieck; ühele selle valdkonna põhiküsimusele (kas igal Banachi ruumil on a.o.?) andis (negatiivse) vastuse Enflo aastal 1972. Tänapäeval paeluvad a.o.-d paljusid Banachi ruumide uurijaid, kuna selles vallas on mitmeid pikka aega lahendamata jäänud probleeme. Väitekirja põhieesmärk on uurida kommuteeruvat tõkestatud a.o.-t (ja selle kompaktset versiooni). Ühelt poolt on see omadus üldjuhul nõrgem kui kommuteeruv meetriline a.o. või lõplikumõõtmelise lahutuse omadus, teiselt poolt aga tugevam kui tõkestatud a.o. Väitekirja teises peatükis tutvustatakse lugejale a.o.-te erinevaid versioone. Kolmandas peatükis tõestatakse, et Willise poolt konstrueeritud meetriline kompaktne aproksimeeriv pere Willise ruumil XW on kommuteeruv, niisiis näidatakse, et kommuteeruv meetriline kompaktne a.o. ja a.o. on erinevad omadused. Väitekirja neljandas peatükis parendatakse üht 1988. aastal Godefroy ja Saphari poolt saadud tulemust: näidatakse, kuidas Banachi ruumi X geomeetriline struktuur (M(a,B,c)-võrratus) võimaldab tõsta kommuteeruva tõkestatud kompaktse a.o. ruumilt X kaasruumi X*. Saadud tulemusele leitakse väitekirjas mitmeid rakendusi. Viiendas peatükis keskendutakse ruumile XJS, mille konstrueerisid aastal 1996 Johnson ja Schechtman. Ruumil XJS ei ole meetrilist a.o.-t, kuid on, nagu tõestatakse väitekirjas, kommuteeruv 6-tõkestatud a.o. Kuuendas peatükis võetakse kasutusele uus mõiste – asümptootiliselt kommuteeruv tõkestatud a.o. Näidatakse, et kui Banachi ruumil on asümptootiliselt kommuteeruv tõkestatud a.o., siis tal on separaabel lokaalse täiendatavuse omadus tugeval kujul.