Coming dissertations at Uppsala university
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Precarious Paths to Democracy: Electoral Violence and the Struggle for Democratization
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-539354
Although nearly all states have adopted multiparty elections, democracy still struggles to firmly take root in many parts of the world. This dissertation examines the relationship between electoral violence and democratization using a multi-method approach. Each of the four essays takes a unique perspective on the link between electoral violence and democratization, focusing on citizens, political parties, and constitution-making processes. Essay I explores how electoral violence dampens the democratizing effects of repeated elections, finding that only peaceful elections contribute to liberal democracy. Essay II analyzes citizen responses to government-perpetrated electoral violence. Essay III examines how political violence influenced interparty negotiations during Turkey’s 2011–2013 constitution-making process. Essay IV finds that in hybrid regimes, negotiated constitutional reforms can reduce government-led electoral violence but have little impact on violence perpetrated by non-state actors. The dissertation makes three main contributions. First, it offers nuanced insights into how electoral violence undermines democratization across multiple dimensions and levels. The findings highlight the importance of adopting a partisan lens to grasp how violence affects different political actors and constituencies. Second, the dissertation highlights an understudied relationship between electoral violence and constitution-making. It demonstrates the conditions under which constitutional reform can help mitigate violence and when it cannot. The findings also highlight how violence poses challenges to constitution-making, underscoring the complexity of implementing democratic reforms when violence and polarization persist. Third, the research elucidates how partisanship shapes the impact of electoral violence on support for democracy. It reveals that while opposition supporters may push for democratic reforms or resist autocratization in the face of government-perpetrated electoral violence, incumbent supporters and non-partisans remain, on average, unmoved. This complicates efforts to advance and protect democracy if intraparty accountability toward violent incumbents is low.
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Enterobacterial colonization of enteroids and colonoids : Interplay with the epithelial surface and inflammasomes
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-539529
The model enteropathogens Salmonella enterica serovar Typhimurium (S.Tm) and Shigella flexneri (S. flexneri) colonize the intestinal lumen and target the apical surface of intestinal epithelial cells (IECs) for invasion. Intraepithelial bacterial populations are restricted by IEC inflammasomes, cytosolic multiprotein complexes that assemble upon detection of bacterium-derived molecules and induce infected IEC death and extrusion. The recent development of non-transformed, purely epithelial enteroid and colonoid models has opened up venues for physiologically relevant mechanistic studies at high spatial and temporal resolution. In this thesis, we employed live-cell imaging in enteroids and colonoids to study how virulence factor modules governing host cell surface targeting and interaction with inflammasomes shape S.Tm and S. flexneri epithelial colonization strategies.
In Paper I, we found that S.Tm invasion induced tissue-scale epithelial contractions via activation of the IEC-intrinsic NAIP/NLRC4 inflammasome, and myosin-based propagation of the contractile response to surrounding IECs. This response preceded infected IEC extrusion and resulted in local tissue compaction to prevent loss of epithelial integrity during infection. In Paper II, enteroid microinjection was employed to map the stages of S.Tm epithelial colonization and identify luminal expansion and cycles of IEC invasion, intraepithelial replication and infected IEC extrusion as collaborative pathways to ensure efficient colonization of both luminal and epithelial niches. In Paper III, parallel enteroid and colonoid infections characterized an S.Tm apical targeting module comprised of flagellar motility and the SPI-4-encoded SiiE adhesin system to foster abundant, but short-lived, invasion foci, terminated by prompt induction of IEC death and extrusion. Low S. flexneri invasion efficiency, in contrast, is compensated by an intraepithelial expansion module coupling OspC3-mediated inflammasome suppression with IcsA-driven lateral spread to evade restriction by IEC death and extrusion. In Paper IV, we developed a simplistic high-throughput infection model to assess host cell surface determinants involved in S.Tm targeting. Chemical cell surface manipulations and ectopic glycoprotein expression established that glycocalyx constituents and bacterial cell surface appendages represent size-dependent steric barriers towards invasion. Hence, while adhesins are necessary to penetrate the apical IEC glycocalyx, a naked host cell membrane rich in cholesterol would be the preferred surface for S.Tm targeting.
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Gaze onto language development : Exploring the Links Between Early Statistical Learning, Word Recognition, and Vocabulary Growth in Infancy and Beyond
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-539545
This thesis aimed to investigate early mechanisms related to language development, with a focus on statistical learning (SL), word recognition, and their influence on later vocabulary. The thesis thus focused on three main goals; first, to explore the role of SL in early language development; second, to determine whether early word recognition tasks can capture individual differences in vocabulary during infancy; and third, to examine how cardinal recognition relates to abstract number word learning in early childhood. Study I employed eye-tracking tasks that assessed learning of associations, sequential patterns, and probabilities in visual and visual-auditory domains. The results showed that associative learning at 10 months predicted expressive vocabulary at 18 months, and sequence learning at both 10 and 18 months predicted receptive and expressive vocabulary at 18 months. However, general probability processing did not show a significant connection to later vocabulary. These findings suggest that broader learning abilities, such as associative and sequence learning, play a role in language development. Study II investigated the effectiveness of eye-tracking paradigms in capturing individual differences in word recognition in infancy and how these relate to vocabulary in toddlerhood. Results indicated that infant’s ability to look at the correct referent of a label was not stable during infancy but became more stable and predictive of vocabulary in toddlerhood. Additionally, infants’ ability to respond to matching stimuli at 11.5 months was linked to both receptive and expressive vocabulary up to 24 months. Study III examined how cardinal recognition contributes to learning abstract number concepts in children aged 2-4. Results showed that subset knowers (children who know some but not all number words) could identify all small numbers (1-4), suggesting that an approximate understanding emerges before an exact understanding of numbers. However, future research is needed to clarify how this ability develops. Together, these studies suggest that both SL and early word recognition are involved in vocabulary development, and that these abilities may evolve and interact over time, highlighting the complexity of language acquisition. Furthermore, word recognition appears to aid in the learning of both concrete and abstract words as development progresses.