Appendices

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Figure 9: Visualization of document citations and relatedness. The distance between two

documents in the visualization approximately indicates their relatedness of the journals in

terms of methodology. The size of the label and circle of a document is determined by

the citation weight/impact of that documents, whereas the position of a term, determines

the cluster of publication year to which the document belongs. Lines between documents

represent links.

Figure 10: Density visualization of document citations. The positioning of the terms in

this figure is the same with that of Figure 9. The density ranges from highly dense points

to low dense points.

in early childhood and gradually wanes into adulthood as a result of slow acquisition of

immunity with age and time. Also, it can be seen that the prevalence in adults is highest

at intermediate infection rates. This is consistent with the infection pattern summarized

by Boyd for tropical Africa [60] and also with the speculations of some epidemiologist

that partial control, which leads to a moderate reduction of transmission from initially high

levels, could increase adult prevalence [148], [63]. While immunity to malaria generally

rises with age, especially in places with the highest forces of infection and stabilizes at

adulthood, this increase with respect to age is not noticeable at low force of infection.