Browsing by Author "Weerasinghe, T."

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    Acute Toxicity and Sub-lethal Effects of Chlorpyrifos to Three Larvivorous Fish, Poecilia eticulate Aplocheilus dayi, and Rasbora daniconius
    (University of Kelaniya, 2012) Ganehiarachchi, G.A.S.M.; Amarasinghe, L.D.; Weerasinghe, T.
    The insecticide belonging to the organophosphate group, chlorpyrifos 40 % EC, is reported to be highly toxic on fish and it is under restricted usage globally. This chemical is used by Dry Zone chena cultivators and hence, there is a possibility of contaminating the bordering water sources rich with larvivorous fish by tracer amounts of this chemical. Two naturally occurring fish species, Aplocheilus dayi (nalahandaya) and Rasbora daniconius (dandiya) and introduced fish species, Poecilia reticulata (wild guppy) are among the potential larvivorous fish in Sri Lanka. The present study was carried out to find out; acute toxicity of chlorpyrifos 40% EC (commando™), to Aplocheilus dayi, Rasbora daniconius and Poecilia reticulata, effects of sub-lethal concentrations of chlorpyrifos on offspring production and on histological alterations in the gill structure. The exposure media contained a series of concentrations (50, 5, 0.5 and 0 μg/l) of chlorpyrifos 40 EC in glass aquaria. Based on the mortality data, LC50 (24 hr) value of chlorpyrifos 40 EC for Aplocheilus dayi, Rasbora daniconius and Poeceilia reticulata was estimated as 0.514μg/l, 0.472 μg/l and 0.882μg/l respectively. It was also revealed that chlorpyrifos 0.5 μg/l of sub-lethal level to P. reticulata has induced production of hatchlings (mean number of 15 hatchings per female per day) whereas no production of hatchings was observed in other treatments during the exposure period. Histopathological study of the gills exposed to 5 and 50 μg/l of chlopyrifos for 48 hr showed hypertrophy of gill arches, lifting and degeneration of lamella epithelium, degeneration of gill filaments and vasodialation in the lamella axis of both Rasbora daniconius and Poecilia reticulata. This study concludes that LC50 values vary for three fish species tested and Poecilia reticulata is more resistant than the other two species. The sub-lethal levels of contaminants of chlorpyrifos 40EC cause histological and physiological aberration in freshwater fish.
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    Development and validation of a cardiovascular risk prediction model for Sri Lankans using machine learning.
    (Public Library of Science, 2024-10) Mettananda, C.; Sanjeewa, I.; Arachchi, T.B.; Wijesooriya, A.; Chandrasena, C.; Weerasinghe, T.; Solangaarachchige, M.; Ranasinghe, A.; Elpitiya, I.; Sammandapperuma, R.; Kurukulasooriya, S.; Ranawaka, U.; Pathmeswaran, A.; Kasturiratne, A.; Kato, N.; Wickramasinghe, R.; Haddela, P.; De Silva, J.
    INTRODUCTION AND OBJECTIVES Sri Lankans do not have a specific cardiovascular (CV) risk prediction model and therefore, World Health Organization(WHO) risk charts developed for the Southeast Asia Region are being used. We aimed to develop a CV risk prediction model specific for Sri Lankans using machine learning (ML) of data of a population-based, randomly selected cohort of Sri Lankans followed up for 10 years and to validate it in an external cohort.MATERIAL AND METHODS The cohort consisted of 2596 individuals between 40-65 years of age in 2007, who were followed up for 10 years. Of them, 179 developed hard CV diseases (CVD) by 2017. We developed three CV risk prediction models named model 1, 2 and 3 using ML. We compared predictive performances between models and the WHO risk charts using receiver operating characteristic curves (ROC). The most predictive and practical model for use in primary care, model 3 was named "SLCVD score" which used age, sex, smoking status, systolic blood pressure, history of diabetes, and total cholesterol level in the calculation. We developed an online platform to calculate the SLCVD score. Predictions of SLCVD score were validated in an external hospital-based cohort.RESULTS Model 1, 2, SLCVD score and the WHO risk charts predicted 173, 162, 169 and 10 of 179 observed events and the area under the ROC (AUC) were 0.98, 0.98, 0.98 and 0.52 respectively. During external validation, the SLCVD score and WHO risk charts predicted 56 and 18 respectively of 119 total events and AUCs were 0.64 and 0.54 respectively.CONCLUSIONS SLCVD score is the first and only CV risk prediction model specific for Sri Lankans. It predicts the 10-year risk of developing a hard CVD in Sri Lankans. SLCVD score was more effective in predicting Sri Lankans at high CV risk than WHO risk charts.
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    Knowledge regarding preventive measures of COVID- 19 and associated factors among employees of selected companies in Colombo area, Sri Lanka
    (Faculty of Medicine, University of Kelaniya, Sri Lanka, 2021) Weerasinghe, T.; Goonewardene, C.S.E.
    Introduction: Due to the COVID 19 pandemic, the demand for Fast Moving Consumer Goods (FMCG) increased. In order to have a continuous supply of goods, employees’ knowledge on preventive methods of COVID 19 is important. Objectives: To describe the knowledge regarding preventive measures of COVID 19 and their associated factors among employees of selected companies in Colombo area. Methods: This study was carried as a web based descriptive cross-sectional study. Employees of selected companies located in 2A and 2B administrative districts of Colombo municipality area was selected using snowballing sampling method. 105 participants filled the online google form. Descriptive statistics was analyzed by using SPSS version 26.0 and Chi square test was used to determine the relationship between the variables. Statistical significance was taken as p<0.05. Results: Mean age of the participants was 37.05 (SD±12.78). Majority were male (75.2%). Almost half 49.5% (N=52) of participants showed overall good knowledge. Majority knew about the causative agent and the origin of CO VID 19. Regarding treatment of COVID 19, majority knew there is no cure for COVID 19 but believed antibiotics are used as first line treatment. Majority believed drinking tea, exposure to higher temperatures more than 25 0C prevents the disease. Interestingly, 53.3% thought asymptomatic person cannot transmit the disease. Being female, age under 35 years and having higher education was associated with higher knowledge scores, however these were not statistically significant (p>0.05). Conclusions: Only half 49.5% (N=52) had good knowledge regarding CO VID 19. Correct knowledge should be disseminated to the employees regarding COVID 19.
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    Phytoplankton and Zooplankton Community Dynamics and Aspects of Food of Two Fish Species in Two Streams and Two Lakes in Presence and Absence of Anophelese Mosquito Larvae in Mahaoya, Sri Lanka
    (University of Kelaniya, 2012) Amarasinghe, L.D.; Ganehiarachchi, G.A.S.M.; Ruchirani, C.; Weerasinghe, T.
    Plankton samples were collected using plankton nets to examine the phytoplankton and zooplankton community dynamics in two streams: namely, Mahaoya, and Panajjawa Oya and two lakes: namely, Bubula Lake and Wagaspitiya Lake in Mahaoya, Ampara district, Sri Lanka. The samples were collected in two consecutive periods in May and August 2011. Aplocheilus dayi and Rasbora daniconius, two naturally occurring fish species were collected (n=50) using cast nets to examine their food aspects in absence of Anopheles mosquito larvae in May 2011 and in their presence in August 2011. Of the total plankton community, only about 28% (14 species) represented zooplanktons while 72% (55 species) were phytoplanktons. Total 14 zooplankton species belonged to; Class Branchiopoda (5 species); Class Lobosa (1 species); Class Maxillopoda (4 species); and Class Monogononta (4 species), and 55 species of phytoplankton population belonged to Class; Chlorophyta (24 species); Class Cyanophyta (11 species); Class Bacillariaphyta (10 species); Class Ochrophyta (4 species); Class Euglenophyta (4 species); Class Heterokontophyta (2 species). The zooplankton population of two streams was dominated by Chromogaster spp. (40 - 80 /ml) while that of two lakes, Bubula and Wagaspitiya were dominated by Eucyclops spp.(120/ml) and Cyclops spp. (80/ml) respectively. The phytoplankton population in all the four water bodies was dominated by Closterium spp. (200-400/ml). The above data reveals that the phytoplankton diversity in two lakes is greater (total of 26 species/taxa) than that of two streams (total number of 14 species/taxa) but, there was no difference in zooplankton diversity between the two habitats. Density and diversity of both phytoplankton and zooplankton in each site between two consecutive sampling occasions (soon after heavy rains in absence of mosquito larvae and during the dry spell in presence of mosquito larvae) did not vary significantly. Gut analysis of two naturally occurring fish species, Aplocheilus dayi and Rasbora daniconius revealed that both of their diets mainly composed of crustaceans 40%, insects 35% and algae, detritus, diatoms and plant parts 25% by number, in presence of mosquito larvae in the habitats in August 2011.
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    Sleep quality and factors associated with poor sleep quality among undergraduates of a selected university in Sri Lanka: A descriptive cross-sectional study
    (Faculty of Medicine, University of Kelaniya, Sri Lanka, 2021) Weerasinghe, T.; Jayamaha., A.R.
    Introduction: Poor sleep quality can lead to daytime performance, increase the risk of motor-vehicle and occupational accidents, exacerbate medical, neurologic, and/or psychiatric conditions, and diminished quality of life. The undergraduate studies were strenuous and can lead to poor sleep. There is a paucity of evidence related to the sleep quality of undergraduate students of Sri Lanka. Objectives: The objective of the study was to evaluate the sleep quality among undergraduates of a selected university in Sri Lanka. Methods: A descriptive cross-sectional study was conducted among 207 KIU undergraduates. Upon the ethical clearance (KIU/ERC/21/68), a self-administered questionnaire in a google form shared through emails among eligible undergraduates. The sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). The data were analysed using descriptive statistics and chi-square test. IBM SPSS v.25 was used as data analysis tool. Results: Majority of undergraduates (81%) were females, with a mean age of 26±6 years. The mean hours of sleep of the undergraduates were 6±2 hours. The sleep quality of 62% of undergraduates was poor (PSQI score<5) and the mean Global PSQI score was 6.73±3.35. Employment parallel to undergraduate studies (p=0.001), following a degree program in health science stream (p=0.02), were significantly associated with poor sleep. Conclusion: Study revealed that the majority of undergraduates having poor sleep quality and appropriate measures need to be taken to improve the sleep quality.
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    The Connection of Employer Branding to Recruitment: A Critique
    (Department of Human Resource Management, Faculty of Commerce and Management Studies, University of Kelaniya, Sri Lanka, 2018) Weerawardane, S.; Weerasinghe, T.
    The present paper reviews and summarizes the key findings of research on the connection of employer branding to employee recruitment with the prime focus of bridging the lacuna in extant literature, due to the inconsistency of aforesaid association across different contexts. Hence, building on social identity theory and job signaling theory, a content analysis of relevant research articles up to date was conducted. It is found that, more the organization/employer looks prestigious the more potentials will get attracted to the organization as being a member of it will improve the self-image too. Also found that, more the organizational attributes do match the personality / personalities of job seeks and communicate it properly, more the potentials will get attracted. The findings of the current review support the general notion that the congruence between individual identity and organizational identity plays a critical role in employer branding which in turn positive outcomes in the domain of recruitment.
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