Björn Olsen

Migratory birds play a dual role as potential reservoirs of tick-borne pathogens, and potential dispersers of pathogen-containing ticks during their migratory journeys. Ixodes ricinus, a prevalent tick species in Northern and Western Europe, serves as a primary vector for Anaplasma phagocytophilum—a bacterium with implications for human and animal health. There is limited information available regarding A. phagocytophilum in birds. Our investigation focused on A. phagocytophilum prevalence in ticks collected from migratory birds in southeastern Sweden. The identification of ticks involved both molecular analyses for species determination and morphological classification to ascertain the developmental stage. The presence of A. phagocytophilum was determined using real-time PCR. Of the 1115 ticks analyzed from 4601 birds, 0.9% (n = 10), including I. ricinus and Ixodes frontalis, tested positive for A. phagocytophilum. Notably, common blackbirds (Turdus merula) yielded the highest number of A. phagocytophilum-infected ticks. The findings suggest that A. phagocytophilum is present in a small proportion of ticks infesting migratory birds in southeastern Sweden. Consequently, the role of birds as hosts for ticks infected with A. phagocytophilum appears to be low, suggesting that birds seem to play a minor indirect role in the geographic dispersal of A. phagocytophilum.

Influenza A virus (IAV) pandemics result from interspecies transmission events within the avian reservoir and further into mammals including humans. Receptor incompatibility due to differently expressed glycan structures between species has been suggested to limit zoonotic IAV transmission from the wild bird reservoir as well as between different bird species. Using glycoproteomics, we have studied the repertoires of expressed glycan structures with focus on putative sialic acid-containing glycan receptors for IAV in mallard, chicken and tufted duck; three bird species with different roles in the zoonotic ecology of IAV. The methodology used pinpoints specific glycan structures to specific glycosylation sites of identified glycoproteins and was also used to successfully discriminate α2-3- from α2-6-linked terminal sialic acids by careful analysis of oxonium ions released from glycopeptides in tandem MS/MS (MS²), and MS/MS/MS (MS³). Our analysis clearly demonstrated that all three bird species can produce complex N-glycans including α2-3-linked sialyl Lewis structures, as well as both N- and O- glycans terminated with both α2-3- and α2-6-linked Neu5Ac. We also found the recently identified putative IAV receptor structures, Man-6P N-glycopeptides, in all tissues of the three bird species. Furthermore, we found many similarities in the repertoires of expressed receptors both between the bird species investigated and to previously published data from pigs and humans. Our findings of sialylated glycan structures, previously anticipated to be mammalian specific, in all three bird species may have major implications for our understanding of the role of receptor incompatibility in interspecies transmission of IAV.

The chapter discusses theory development and aims to gain insight into theory development and how theory may be used in the presentation of a research project. A number of concepts are discussed, namely semantic assumptions, formal and factual interpretations, reference base, and epistemological hypotheses.

In this chapter, we focus on the following problem: How can conceptual generalization be used in the social sciences?

This chapter discusses understanding and explaining and focuses on the difference between understanding a phenomena/problem and explaining it. The chapter also shows how this insight can be used in the presentation of a research project.

This chapter discusses simplification and aims to present why simplification is fundamental to any research project. The chapter discusses critical elements, composition, limits, and relationships.

This chapter is about interpretation and aims to gain insight into the interpretative process. The chapter discusses the concepts of interpretation, conceptualization, partial truths, and meaning.

This chapter is about development of models and aims to gain understanding of the difference between various types of model. Additionally, the chapter shows how this insight can be used in the presentation of a research project. Analytical, conceptual causal, and empirical causal models are discussed.

This chapter is about uncovering patterns and aims to gain insight into how patterns can be uncovered in social systems and into how this can be used in the presentation of a research project. In this chapter, we look into patterns and empirical generalization.

To highlight the most common research errors.