Browsing by Author "Somarathna, M."

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Evaluation of the genetic diversity of Domain II of Plasmodium vivax Apical Membrane Antigen 1 (PvAMA-1) and the ensuing strain-specific immune responses in patients from Sri Lanka
(Elsevier, 2011) Dias, S.; Somarathna, M.; Manamperi, A.; Escalante, A.A.; Gunasekera, A.M.; Udagama, P.V.
Antigenic polymorphism displayed by malaria parasites is a skewed schema to escape the host immune system. The prevailing genetic diversity at domain II of the Plasmodium vivax Apical Membrane Antigen-1 (Pvama-1DII) was characterized in 64 single clone P. vivax isolates from Sri Lanka, where unstable malaria prevails with low intensity. In Sri Lanka, the Pvama-1DII gene showed meager meiotic recombination with the enclosure of single nucleotide polymorphisms (SNPs). Eleven amino acid (a.a.) variant positions defined 21 a.a. haplotypes with 9 unique to the island, where the predominant haplotype, H1, was identical to the reference Salvador I strain. A further 376 globally dispersed isolates defined 38 a.a. haplotypes (H22-H59), with 4 and 26 haplotypes exclusive to India and Thailand, respectively. The phylogenetic tree revealed no clustering, where most isolates had a very recent common origin. The polymorphism detected in PvAMA-1DII B and T cell epitopes evidenced an immune evasion mechanism exploited by the parasite. Majority of Sri Lankan patients developed antibody responses to both conformational and linear B cell epitopes. The ensuing strain-specific immunity due to extensive antigenic polymorphism was evaluated by aligning a.a. sequences of PvAMA-1DII with the homologous total (IgM+IgG) antibody responses assayed by in-house established indirect ELISAs against 7 PvAMA-1DII overlapping synthetic peptides, P01-P07. While the antibody responses to P01-P03, P06, P07 harbouring P. vivax clinical isolates with polymorphic a.a. haplotype to Sal I was clearly strain-transcending (cross-reactive), individuals with isolates identical to the Sal I strain observed varying antibody prevalence against the seven PvAMA-1DII Sal-I synthetic peptides, with the highest prevalence detected against P04. Synthetic peptide P04, spanning a.a. positions 302-324 of the PvAMA-1DII of the Sal I strain that included the epitope recognized by the invasion inhibitory 4G2 monoclonal antibody of PfAMA-1, was highly conserved in all 440 local and global P. vivax isolates examined. A functional role for this region is reinforced by the highly immunogenic nature of P04, and could point towards a presumably "protective" anti-P04 antibody response that elicited an isotype switch from IgM to IgG, with increasing exposure to malaria exclusively in endemic residents. Thus the conserved and seemingly "protective" nature of the domain II loop of PvAMA-1 makes it a putative contender to be included in a cocktail vaccine against P. vivax asexual erythrocytic stages in Sri Lanka.
How political advertisements in Television media effected to the Presidential election 2010
(11th Annual Research Symposium, Faculty of Graduates Studies, University of Kelaniya Sri Lanka, 2010) Jayasekara, A.H.D.; Somarathna, M.; Herath, H.M.D.B.; Television and politics, Sri Lanka
Throughout history politicians have used various methods, such as whistle-stop speeches, political advertising and political rallies, to achieve their "primary goal, the winning of votes. Politicians have found that it is most advantageous to use political advertising to persuade voters. Political advertising has always been a central feature of every culture. As encountered in the mass media, it is pervasive and inescapable Commercial advertisements are widely accepted as fair and legitimate marketing. Political advertisements deal with the production, dissemination, procession and effects of information, both through media and interpersonally, within a political context. In recent years, political advertising has become essential to campaign strategy, and many regard it as far more intrusive than routine commercial advertising. Because political advertising, unlike product advertising, must get results in a short period of time, political practitioners use several kinds of political advertising: image, issue and negative advertising. In television media it has big power to change behavior of the audience. Certain political activists have been struggling with the same task even longer, attempting to influence election outcomes by using media to communicate with the voters. Candidates issue position, candidate image, voter group membership and retrospective voting. The message of the advertisement is what ideas that the candidate wants to share with the voters. The message often consists of several talking points about policy issues. The points summarize the main ideas of the political advertisements and are repeated frequently in order to create a lasting impression with the voters The Objective is this research is to identify how television political advertisement effected to the presidential election 2010.Methodology of this study is survey method and comparative method. Observation and questionnaires used as data collection method. We collected data randomly from people in every district. We distributed 100 questionnaires per district. We considered the content of the political advertisements. We focused only two main candidates for this research. We considered nominations accepted date in 2009 to date which the election was held in 2010.When we analyzing data on last presidential election we paid our attention on age limit of the audience, and the television channel which was telecasted these commercials. According to our research we found television advertisement helped to create public opinion. Nationality and victory of war used to create these television commercials. Advertisements which was telecasted on ITN channel created more impact on the audience. This is because ITN has a wide coverage more than the other channels. We found eighteen advertisements which remembered to the audience. There were so many political advertisements at that time but, ?Tharunyata Hetak? was the most effected advertisement which telecasted on television.Because so many stars used to create that advertisement. Content, visuals, music, colours used to political advertisements to enhance their message.