A vast number of studies have been completed on the virulence determinants of Yersinia spp.; however, the focus of many of these studies has been on the virulence plasmid and the plasmid-encoded Type three secretion system. Nevertheless, many chromosomal genes whose products are directly involved in virulence have also been identified. Some of these critical virulence determinants are outer membrane proteins. Outer membrane proteins of Gram-negative bacteria often have important physiological roles; however, some have also been found to be important for pathogenesis. In this thesis, we investigated two Yersinia. pestis outer membrane proteins, Ail and OmpA, and their roles in virulence. We provide evidence that Y. pestis Ail is a highly expressed outer membrane protein that is absolutely essential for Y. pestis to resist the killing action of the complement system present in human blood and tissues, as well as the blood and tissues of other mammalian hosts. Furthermore, Ail was important for virulence in a Y. pestis-Canorhabditis elegans model of infection.The work in this thesis also provided the first evidence that another surface-exposed outer membrane protein, termed OmpA, is required for both Yersinia pseudotuberculosis and Y. pestis to survive and proliferate intracellularly in macrophages. Finally, we provide evidence that Y. pestis has a functional small RNA MicA that controls the expression of OmpA. This is the first demonstration of sRNA-mediated regulation of a Yersinia virulence factor. This work has paved the way for future studies on the role of outer membrane proteins in virulence, particularly the role of Ail and OmpA.

Sexual selection was defined by Darwin in 1871 as selection acting solely on reproduction success. It is known to act on males resulting in extravagant ornamentations or other attributes, but in recent years more studies have shown that sexual selection also act on females. There is empirical evidence in several taxa that the secondary sexual ornament also acts as a measurement on the females’ reproductive quality, it is an honest trait. In Gallus gallus the comb has been found to be an honest ornament. Quantitative Trait Loci have been found on chromosome 1 and 3 for comb- and egg size. The honesty of the comb is hypothesized to be caused by either a pleiotropic effect gene linkage. In this study an 8th generation Advanced Interline Cross was used to guarantee maximum recombination of alleles to observe phenotypic effects. 177 females were detained during 4 weeks to measure fecundity. Egg number, mean egg weight and total egg size were correlated to comb size: length, area and weight. Correlation between comb size and total egg weight were found to be negative, suggesting the comb to be a dishonest signal. The phenotypic measurements observed in this study suggest that the genes for egg production and comb size are linked, and this linkage has been broken in the F8 analysed in this study.

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Studiens syfte är att undersöka hur olika yrkeskategorier inom vuxenutbildningens utbildning i svenska för invandrare (sfi) verkar tillsammans inom ramarna för verksamheten. Genom individuella intervjuer framkommer möjligheter och svårigheter. Empiri har bearbetats genom tematisk analys. Den teoretiska utgångspunkten för studien är en modell om samarbete, samordning och samverkan genom olika grader av vertikal respektive horisontal integrering av styrningsmekanismer och frivilliga initiativ. Resultatet visar att det förekommer en mängd olika tillfälliga samarbeten. De intervjuade ger exempel på yrkeskategorier som möts i det vardagliga arbetet. Dessutom sker arbete mellan olika yrkeskategorier i en mer samordnad form genom team. Vidare synliggörs respondenternas upplevelser av värdet av att samarbeta, exempelvis stärkta relationer och en bättre arbetsmiljö. Ett annat värde som lyfts fram är den ökade möjligheten för personal att identifiera behov av stöd hos eleverna, som leder till bättre anpassningar av undervisningen. Resultatet visar också hur verksamheten samordnas genom team, samt potential för samverkan. Samverkan mellan yrkeskategorier uppnås inte fullt ut idag inom sfi. Slutsatserna visar att det finns en samsyn hos chefer och övriga yrkeskategorier gällande vilka mekanismer som försvårar respektive möjliggör samverkan. Rutiner för samverkan saknas. Det medarbetarna också efterfrågar är någon som leder arbetet och beslutar att man ska samarbeta och hur det ska gå till. Det vill säga någon som bär ansvaret för att planera, genomföra och följa upp samverkan. / The aim of this study is to investigate how different occupational categories within adult education in Swedish for immigrants (SFI) interact within the framework of their common business. As a method for carrying out the study, I have used qualitative interviews. The data material presents opportunities and difficulties that appear around working together. The empirical material has been processed through thematic analysis. The theoretical starting point for the study is a model of different degrees of vertical and horizontal integration for understanding collaboration. The result shows that there are a variety of temporary collaborations. Through interviews the study give examples of professional categories that meet in everyday work. In addition, work takes place between different professional categories in a more coordinated form through teams. Furthermore, the respondents' experiences of the value of collaborating, such as strengthened relationships and a better working environment, are made visible. Another highlight that is mentioned is the increased possibility for staff to identify the need for support from the students, which leads to better adaptations of teaching. The result also shows how the business is coordinated through teams, and the potential for collaboration. Cooperation between professional categories is not fully achieved today within sfi. The conclusions show that there is a consensus among managers and other occupational categories considering which mechanisms make it difficult or possible to cooperate. There are no routines for collaboration today. What employees also demand is someone who leads the work, makes decisions and bears the responsibility of planning, implementing and following up the collaboration.