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Coming dissertations at Uppsala university

  • Polyporoid fungi of Tanzania : Taxonomy, transcriptomics and biochemical analyses of Kusaghiporia usambarensis and Piptoporellus baudonii Author: Juma Mahmud Hussein Link: Publication date: 2020-03-26 08:38

    Polyporoid fungi refers to basidiomycetes with fruiting bodies with the hymenium located to the inner surfaces of pores or narrow tubes. The majority of polyporoids belongs to Polyporales. Most Polyporales are saprobes, but some are plant pathogens. The overall aim of this thesis was to study the taxonomy, systematics and chemistry of the two species Kusaghiporia usambarensis (saprobic) and Piptoporellus baudonii (a plant pathogen) collected from Tanzania, using morphological and molecular approaches, combined with transcriptomics and pharmacognostic investigations.

    The main contribution of this thesis includes the description a new genus with the new species K. usambarensis from the Usambara Mountains, Tanzania; investigation of the chemical composition of volatile compounds from this medicinal mushroom; isolation and structure determination of a novel and most abundant peptide in K. usambarensis, and further to elucidate the phylogenetic position of Piptoporellus baudonii (formerly known as Laetiporus baudonii) by using a four molecular markers dataset.

    Paper I was conducted applying a classical taxonomic approach, including both morphological and phylogenetic analyses, to describe a new genus and species K. usambarensis. Paper II, investigated volatiles and volatile derivatives in dichloromethane extracts of K. usambarensis analysed by GC-MS and NMR spectroscopy. The main elements were phenols, and esters, compounds that may explain the formerly reported antioxidant activity and traditional medicinal use of the mushroom. In paper III, screening of peptides in K. usambarensis revealed a novel cysteine-rich peptide, highly expressed at gene level and the most abundant compound in the fruiting body. Combined LC-MS and transcriptome analyses were used to determine the peptide sequence, and subsequently NMR spectroscopy to determine the 3D structure of the novel peptide, kusaghitide. In paper IV molecular techniques were used to elucidate the phylogenetic position of the parasitic Laetiporus baudonii. Phylogenetic analyses of combined 5.8S, nrLSU, nrSSU, and TEF1 gene sequences placed L. baudonii in the genus Piptoporellus, hence the new combination Piptoporellus baudonii was proposed. This thesis has contributed to build capacity in the fields of mycology, systematics and pharmacognosy in order to reinforce ecological knowledge and ethnopharmaceutical research for future drug discovery in Tanzania and Africa at large.

  • Evidential marking in spoken English : Linguistic functions and gender variation Author: Erika Berglind Söderqvist Link: Publication date: 2020-03-26 07:55

    This thesis investigates the marking of evidentiality in spoken British English. Evidentiality is the linguistic expression of whether and how a speaker/writer has access to evidence for or against the truth of a proposition, and it is usually manifested in the form of sensory evidentiality (e.g. I saw Sam leave), hearsay evidentiality (e.g. They say Sam left), or inferential evidentiality (e.g. Sam obviously left). In the examples, the bold words exemplify evidentiality markers. The aims of this thesis are to investigate whether there are quantitative differences between women and men in how often they mark evidentiality, and to analyze the functions of evidentiality in interaction in order to formulate an explanation of any gender differences.

    The material comes mainly from the spoken portion of the British National Corpus (BNC), but also from the Diachronic Corpus of Present-day Spoken English (DCPSE). In Article 1, women and men were compared with respect to how frequently they marked inferential evidentiality; gender preferences for specific markers were also analyzed. In Article 2, the effects of speaker gender and speaker age on how frequently evidentiality markers are used were investigated. In Article 3, the marking of evidentiality in conversation was analyzed to explore the potential of evidentiality to be instrumental in relational practice. In Article 4, speakers were ranked according to the extent to which their speech displayed stereotypically feminine or masculine features. The language of a subset of speakers was then analyzed to investigate whether evidential markers are used for different functions depending on gendered styles.

    In the studies of this thesis, women were found to mark evidentiality more frequently than men. Further, the language of women as well as language characterized by a feminine style were found more likely to feature evidential markers referencing evidence that is only accessible to the speaker, whereas the language of men and language characterized by a masculine style are more likely to feature evidential markers referencing evidence that is accessible to other interlocutors in addition to the speaker. Evidential marking was found to often perform relational functions; in particular, evidentiality enables the speaker to negotiate authority in a less face-threatening manner. Evidential marking seems likely to occur when the addressee’s interpretation of an utterance is important to the speaker. Since previous studies have found women’s language to display more often a concern for the experiences of others, this characteristic might partly explain the quantitative gender variation.



  • Effectiveness and cost-effectiveness of indicated preventive interventions for depression in adolescents : An application of health economics methods Author: Richard Ssegonja Link: Publication date: 2020-03-25 07:57

    Unipolar depressive disorders are commonly encountered conditions in clinical practice with about 25% reporting their first episode during adolescence. Longitudinal studies show adolescent depression to be associated with an increased risk of mental illness in adulthood, healthcare usage, poor educational outcomes, unemployment, and dependency on welfare recipiency. Therefore, adolescent depression contributes a high disease burden and impinges a considerable financial strain on society’s limited resources.

    Several preventive interventions have been developed to prevent adolescent depression. Of these interventions, group-based cognitive behavioural therapy (GB-CBT) indicated preventive interventions for depression are well studied and accepted. However, evaluations of their effectiveness and cost effectiveness have yielded conflicting and incomplete results mainly due to methodological limitations.

    Therefore, the overarching aim of this thesis was to investigate the effectiveness and cost-effectiveness of GB-CBT indicated preventive interventions for depression in children and adolescents, and estimate the additional healthcare costs and welfare burden in early to mid-adulthood associated with adolescent depression.

    In study I, GB-CBT indicated preventive interventions for depression in children and adolescents were protective against developing a depressive disorder and also reduced depressive symptoms. The intervention relative effect was noted to decay over time. Study II revealed that adolescent depression was associated with considerable increased healthcare consumption in mid-adulthood compared to the non-depressed peers at a population level. This finding was more pronounced in females with persistent depressive disorder (PDD). Study III showed adolescent depression to be associated with all the forms of social transfer payments (welfare) especially in individuals with PDD and those with early comorbid psychopathologies.

    Study IV demonstrated that GB-CBT indicated preventive interventions for adolescent depression are not only effective but also have the potential to be cost-effective compared to leaving adolescents with subsyndromal depression unattended.

    Findings from studies II and III, emphasized the large financial burden to society in terms of additional healthcare costs and welfare expenditure associated with adolescent depression. Whereas, study I and IV bring forward the message that it is possible to change the course of subsyndromal depression by offering GB-CBT indicated preventive interventions to adolescents with subsyndromal depression. Such an initiative was not only cost-effective compared to not intervening, but also largely cost-saving. Therefore, GB-CBT indicated preventive interventions could be used as part of a stepped care program linking into more specialized care services. The results of this thesis will be useful in decision-making concerning the resource allocation related to adoption and implementation of such preventive measures.