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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.
201

Études sur la morphologie et la physiologie cellulaires du développement de l'oursin

Runnström, J. January 1914 (has links)
No description available.
202

Über einige magnetische Messmethoden nebst magnetischen Untersuchungen an eisen- und manganhaltigen Silikaten

Holm, Erik January 1913 (has links)
No description available.
203

Beiträge zur Geologie des südlichen Teils des Kirunagebiets

Sundius, Nils January 1915 (has links)
No description available.
204

Studien über Konstruktionstypen und Entwicklungswege des Embryosackes der Angiospermen

Palm, Björn January 1915 (has links)
No description available.
205

Heritable epigenetic responses to environmental challenges : Effects on behaviour, gene expression and DNA-methylation in the chicken

Nätt, Daniel January 2011 (has links)
Phenotypic variation within populations is a crucial factor in evolution and is mainly thought to be driven by heritable changes in the base sequence of DNA. Among our domesticated species we find some of the most variable species on earth today. This variety of breeds has appeared during a relatively short evolutionary time, and so far genetic studies have been unable to explain but a small portion of this variation, which indicates more novel mechanisms of inheritance and phenotypic plasticity. The aim of this study was therefore to investigate some of these alternative routes in the chicken, especially focusing on transgenerational effects of environmental challenges on behaviour and gene expression in relation to domestication. In two experiments a chronically unpredictable environment induced phenotypic changes in the parents that were mirrored in the unexposed offspring raised without parental contact. This transmission was especially clear in domesticated birds. A third experiment showed that repeated stress events very early in life could change the developmental program making the birds more resistant to stress later in life. Here, the phenotypic changes were also mirrored in the unexposed offspring and associated with inheritance of gene expression. Epigenetic factors, such as DNA-methylation, could play an important role in the mechanism of these transgenerational effects. A fourth experiment showed that wild types and domesticated chickens differed substantially in their patterns of DNA-methylation, where the domesticated breed had increased amount of promoter DNA-methylation. In line with the previous experiments, this breed also showed increased transmission of methylation marks to their  offspring. Conclusively, parental exposure of environmental challenges that introduce changes in behaviour, physiology and gene expression can under both chronic and temporal conditions be heritably programmed in the parent and transmitted to the unexposed offspring. Since heritable epigenetic variation between wild type and domesticated chickens is stable and numerous, it is possible that selection for favourable epigenomes could add another level to the evolutionary processes and therefore might explain some of the rapid changes in the history of the domesticated chicken.
206

Studien über die proteolytischen Enzyme der Heft und ihre Beziehung zu der Autolyse

Dernby, Karl Gustaf January 1917 (has links)
No description available.
207

Hornborgasjön : en monografisk framställning av dess postglaciala utvecklingshistoria

Sandegren, Ragnar January 1916 (has links)
No description available.
208

Post-glacial marine shell-beds in Bohuslän

Antevs, Ernst January 1917 (has links)
No description available.
209

Protein Structure and Interaction in Health and Disease

Andrésen, Cecilia January 2011 (has links)
This thesis focuses on protein structure, dynamics and interaction and their relation to human disease. In particular, the biophysical and structural properties of both well-ordered and partially disordered proteins are studied using a range of biophysical techniques such as circular dichroism spectroscopy, fluorescence spectroscopy, mass spectrometry and nuclear magnetic resonance spectroscopy. Pseudomonas aeruginosa is a human pathogen due to its multidrug resistance (MDR) caused by overexpression of efflux pump systems. This thesis describes how MDR mutations within the MexR repressor of the MexAB-OprM system reduce the DNA affinity by altering its stability with maintained structure. The oncogenic protein c-Myc is involved in many essential biological functions such as cell proliferation, differentiation and apoptosis and is also highly associated with several forms of human cancers, and where the N-terminal domain is regulated by a plethora of protein interactions. In this thesis the intrinsically disordered N-terminal part of c-Myc and its interactions with the proteins Bin1 and TBP are described. Myc binds Bin1 with maintained disorder in a multivalent manner, which may explain why the onco-protein can interact with such a wide range of binding partners. A similarly dynamic interaction is observed for Myc with the TATA-binding protein (TBP). The essential human multidomain glutaredoxin Grx3 is associated with several biological functions such as redox signaling, proliferation and signal transduction. We have solved the structure and analyzed the dynamic properties in the ps-ns and ms time scale for the two N-terminal domains, providing a platform for further analysis of the Grx3 protein and its interactions. Taken together, this thesis emphasizes the importance of joint structural, biophysical and dynamic studies to better understand protein function in health and disease.
210

Luftväxlingen i marken som ekologisk faktor

Romell, Lars-Gunnar January 1922 (has links)
Särtryck ur: Meddelanden från Statens skogsförsöksanstalt ; 19

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