Liquid Crystal Mediated Bioassay for Protein Detection

Ph.DDOCTOR OF PHILOSOPH

Adsorption Capacity and Phosphate Removal Efficiency of Oyster Shells and its Implications to Chemistry Learning

The aquaculture sector of the Philippines which includes fish pond culture systems faces many challenges and issues such as high concentration of phosphate which does not only affect water parameters but also triggers the occurrence of Harmful Algal Blooms. Hence, this study was conducted to evaluate the adsorption capacity and phosphate removal efficiency of oyster shell powder (OSP) using brackishwater under laboratory conditions as learning resources of chemistry learning. This quantitative research study used Completely Randomized Design (CRD) with three treatments: T1 (Control/Commercial) – 1.5g Calcium carbonate (CaCO3); T2 – 1.5g Oyster Shell Powder (OSP); T3 – 2.5g Oyster Shell Powder (OSP). Results revealed that in terms of surface morphology, the photographs showed irregularity of shapes and different sizes, implying heterogeneity of OSP while, in terms of elemental composition, Calcium and Oxygen are the major elemental composition of the OSP. Further, in terms of Phosphate Adsorption Capacity, One Way ANOVA revealed significant differences (p-value &lt;0.01) among treatments. Further analysis using LSD revealed that commercial calcium carbonate has significantly higher adsorption capacity than oyster shell powder, however, 1.5 g OSP has higher adsorption capacity than 2.5g OSP. Furthermore, in terms of phosphate removal efficiency, One Way ANOVA revealed no significant differences (p-value &lt;0.05). This means that the phosphate removal efficiency of OSP is comparable to commercial calcium carbonate (CaCO3).Moreover, the study's findings act as an educational resource, facilitating a profound comprehension of the practical applications of chemistry principles. It encourages chemistry learners to engage in critical evaluation and practical application of their knowledge, particularly in addressing pressing environmental challenges.</p

Chikungunya Outbreak, South India, 2006

We investigated chikungunya outbreaks in South India and observed a high attack rate, particularly among adults and women. Transmission was facilitated by Aedes aegypti mosquitoes in peridomestic water containers, as indicated by a high Breteau index. We recommended vector control measures and health education to promote safe water storage practices

High rate of subclinical chikungunya virus infection and association of neutralizing antibody with protection in a prospective cohort in the Philippines.

BACKGROUND: Chikungunya virus (CHIKV) is a globally re-emerging arbovirus for which previous studies have indicated the majority of infections result in symptomatic febrile illness. We sought to characterize the proportion of subclinical and symptomatic CHIKV infections in a prospective cohort study in a country with known CHIKV circulation. METHODS/FINDINGS: A prospective longitudinal cohort of subjects ≥6 months old underwent community-based active surveillance for acute febrile illness in Cebu City, Philippines from 2012-13. Subjects with fever history were clinically evaluated at acute, 2, 5, and 8 day visits, and at a 3-week convalescent visit. Blood was collected at the acute and 3-week convalescent visits. Symptomatic CHIKV infections were identified by positive CHIKV PCR in acute blood samples and/or CHIKV IgM/IgG ELISA seroconversion in paired acute/convalescent samples. Enrollment and 12-month blood samples underwent plaque reduction neutralization test (PRNT) using CHIKV attenuated strain 181/clone25. Subclinical CHIKV infections were identified by ≥8-fold rise from a baseline enrollment PRNT titer 50 years old. Baseline CHIKV PRNT titer ≥10 was associated with 100% (95%CI: 46.1, 100.0) protection from symptomatic CHIKV infection. Phylogenetic analysis demonstrated Asian genotype closely related to strains from Asia and the Caribbean. CONCLUSIONS: Subclinical infections accounted for a majority of total CHIKV infections. A positive baseline CHIKV PRNT titer was associated with protection from symptomatic CHIKV infection. These findings have implications for assessing disease burden, understanding virus transmission, and supporting vaccine development

Seroprevalence Survey of Chikungunya Virus in Bagan Panchor, Malaysia

In 2006, an outbreak of Chikungunya virus (CHIKV) of the Asian genotype affected over 200 people in Bagan Panchor village in Malaysia. One year later, a post-outbreak survey was performed to determine attack rate, asymptomatic rate, and post-infection sequelae. Findings were compared with recent CHIKV outbreaks of the Central/East African genotype. A total of 180 residents were interviewed for acute symptoms and post-infection physical quality of life and depressive symptoms. Sera from 72 residents were tested for CHIKV neutralizing antibodies. The estimated attack rate was 55.6%, and 17.5% of infected residents were asymptomatic. Arthralgia was reported up to 3 months after infection, but there were no reports of long-term functional dependence or depression. Symptomatic and seropositive residents were significantly more likely to live in the area with the most dense housing and commercial activities. CHIKV had a high attack rate and considerable clinical impact during the Bagan Panchor outbreak

Reconstruction of 60 Years of Chikungunya Epidemiology in the Philippines Demonstrates Episodic and Focal Transmission

Proper understanding of the long-term epidemiology of chikungunya has been hampered by poor surveillance. Outbreak years are unpredictable and cases often misdiagnosed. Here we analyzed age-specific data from 2 serological studies (from 1973 and 2012) in Cebu, Philippines, to reconstruct both the annual probability of infection and population-level immunity over a 60-year period (1952–2012). We also explored whether seroconversions during 2012–2013 were spatially clustered. Our models identified 4 discrete outbreaks separated by an average delay of 17 years. On average, 23% (95% confidence interval [CI], 16%–37%) of the susceptible population was infected per outbreak, with >50% of the entire population remaining susceptible at any point. Participants who seroconverted during 2012–2013 were clustered at distances of <230 m, suggesting focal transmission. Large-scale outbreaks of chikungunya did not result in sustained multiyear transmission. Nevertheless, we estimate that >350 000 infections were missed by surveillance systems. Serological studies could supplement surveillance to provide important insights on pathogen circulation