http://ir.lib.ruh.ac.lk/handle/iruor/7344 2026-08-18T20:45:14Z 2026-08-18T20:45:14Z Warnasooriya, S.R. Jayasinghe, A.D. Asanthi, H.B. Kodithuwakku, E.P. http://ir.lib.ruh.ac.lk/handle/iruor/21591 2026-08-14T04:02:40Z 2024-03-07T00:00:00Z

Bactericidal effect of nanosilver synthesized with Neolitsea cassia mucilaginous extract. Warnasooriya, S.R.; Jayasinghe, A.D.; Asanthi, H.B.; Kodithuwakku, E.P. This study focused on green synthesis of silver nanoparticles using mucilaginous leaf extracts of Neolitsea cassia and demonstrating the bactericidal effect of the product against Staphylococcus aureus and Escherichia coli, which are common in polluted water. A concentration series of silver nitrate was subjected to four treatments by mixing with separate (a) aqueous and (b) 80% methanol extracts of N. cassia leaves in (c) atmospheric and (d) nitrogen gaseous environments, for comparison. A linear increment of the dry weight of silver nanoparticles was observed with increasing silver nitrate concentration (r = 0.99, p = 0), resulting in higher yields from 80% methanol extracts in an atmospheric environment. As characterized by surface plasmon resonance absorption, energy-dispersive X-ray spectroscopy and scanning electron microscopy, quasi-spherical crystalline silver nanoparticles of 11.7nm average diameter were synthesized. The disk diffusion method showed that the growth of E. coli and S. aureus in culture media was increasingly inhibited with increasing nanoparticle concentration (r = 0.95, p = 0 and r = 0.93, p = 0, respectively). It was concluded that 80% methanol extract in an atmospheric environment was the most productive way to green-synthesize silver nanoparticles from the mucilaginous sap of N. cassia.

2024-03-07T00:00:00Z Atapaththu, K.S.S. Subramaniam, Ganadeepan Sanjaya, Kelum Priyadarshana, Tilak http://ir.lib.ruh.ac.lk/handle/iruor/21172 2026-06-16T03:46:17Z 2024-01-01T00:00:00Z

Spatiotemporal variability of Sri Lankan rainfall From 1990 to 2020. Atapaththu, K.S.S.; Subramaniam, Ganadeepan; Sanjaya, Kelum; Priyadarshana, Tilak Rainfall serves as a cornerstone for numerous sectors, including rain-fed agriculture, hydropower generation, fisheries, tourism, and the stability of coastal ecosystems. Given its pivotal role, understanding rainfall patterns is crucial for informed decision-making and the effective management of these sectors. This study aims to scrutinize the spatiotemporal variation in Sri Lankan rainfall over the past three decades. Utilizing daily rainfall data from 52 stations across the country spanning from 1990 to 2020, this analysis computed monthly, annual, and monsoonal rainfall metrics, meticulously addressing missing data using established methodologies. Employing statistical tools such as Mannslope, temporal variations in rainfall were discerned. Inter-decadal comparisons were conducted, revealing shifts in mean annual rainfall across distinct periods (1991 2000, 2001 2010, and 2011 2020). Spatial distributions of mean decadal rainfall were visualized using ArcGIS, complemented by the Inverse Distance Weighting (IDW) method to interpolate annual values, enhancing spatial comprehension. Significantly increasing trends in rainfall were identified during specific monsoon seasons and inter-monsoon periods at various stations, while notable decreases were observed in others. Interestingly, a substantial increase in rainfall was noted in the dry zone during 2011 2020 compared to 1991 2000, indicative of dynamic shifts in precipitation patterns. These findings underscore the variability of rainfall across Sri Lanka's climatic zones over the past three decades, suggesting potential revisions to current demarcations. Such insights are invaluable for informing policies, strategies, and future research endeavors in climate science and related disciplines.

2024-01-01T00:00:00Z Kumara, H.K.R.S. Atapaththu, K.S.S. Herath, S.S. Vidanapathirana, N.P. Marasinghe, K. http://ir.lib.ruh.ac.lk/handle/iruor/21171 2026-06-16T03:38:04Z 2024-01-01T00:00:00Z

Exploring strategies for developing and expanding Integrated rice-fish farming to enhance food Security in Sri Lanka. Kumara, H.K.R.S.; Atapaththu, K.S.S.; Herath, S.S.; Vidanapathirana, N.P.; Marasinghe, K. Integrated Rice-fish farming (IRFF) represents a symbiotic farming system where fish are cultivated in rice fields. This review aimed to assess the relevance and role of IRFF as a strategic approach to ensure food security in Sri Lanka. In this attempt available information on Integrated Rice Fish farming have been compiled with the support of scientific data bases of Google Scholar, PubMed, Scopus, and Science Direct. According to the literature, the IRFF significantly increased both rice and fish yields compared to their monocultures, and the productions vary with the geographic regions. For instance, IRFF in Indonesia exhibited an increase of their rice production by 22-32% than that of monocultures and similar trends were also observed in West Bengal, India, and Thailand. Considering the Sri Lankan context, as Sri Lankan adults and children especially under five years are prevalent several forms of malnutrition including underweight, stunting and wasting, micronutrient inadequacies. Thus, the development and expansion of rice-fish farming among the rural farming communities is vital as a system that increase both protein, carbohydrate and other micronutrient requirement demand exist specially among rural communities. However, well-planned strategies to develop and expand this system among in Sri Lankan rural paddy farmers are required. The robust political commitment and support from governmental and non-governmental entities are vital for facilitating accessible credits for initial infrastructure, implementing training and awareness programs tailored for smallscale farmers, establishing effective market linkages, conducting adaptive research initiatives, and ensuring the provision of essential inputs such as quality fingerlings. The success of these strategies depends on the active involvement of financial institutions and donor organizations, aimed at empowering farmers and ensuring equitable compensation. In conclusion, this review unveils the significance of IRFF in enhancing food security and outline pathways for its development and expansion in Sri Lanka. Further, rice-fish integration is one of the best options to mitigate the malnutrition issues in rural communities, and particularly important to meet the Sustainable Development Goals (No Poverty (SDG 1), Zero Hunger (SDG 2), Good Health and Well-being (SDG 3)).

2024-01-01T00:00:00Z Kumara, H.K.R.S. Atapaththu, K.S.S. Herath, S.S. Vidanapathirana, N.P. Marasinghe, K. http://ir.lib.ruh.ac.lk/handle/iruor/21170 2026-06-16T03:24:41Z 2023-12-01T00:00:00Z

Exploring ecological and societal functions of Rice-fish farming in the agricultural landscape of Sri Lanka. Kumara, H.K.R.S.; Atapaththu, K.S.S.; Herath, S.S.; Vidanapathirana, N.P.; Marasinghe, K. Rice-fish integration is a symbiotic farming system where fish are reared in rice fields. The information on the potential effects and benefits of the system in the Sri Lankan context is largely unknown and has yet to be discovered. Therefore, this study was accomplished with target scrutiny of societal benefits and ecological function of fish farming in the rice fields of Sri Lanka. The study followed a qualitative case study approach, including literature review and document analysis. Study findings demonstrated that ecologically, the presence of fish in the system contributes to increased nutrient levels for rice plants, simultaneously serving as a natural mechanism for weed and pest control while promoting soil ecology in rice fields. The rice plants, in turn, play a pivotal role in water purification, establishing optimal water temperature conditions, and fostering heightened aquatic diversity. Regarding Sri Lanka, Tilapia and Common Carp are recognized as culturable fish species and traditional and improved rice varieties can coexist with fish under wellmanaged integrated conditions. Further, rice-fish farming would emerge as a powerful tool to generate long term and short-term societal wellbeing in Sri Lanka. Long-term benefits are poverty alleviation by increasing household income, promoting social upliftment, and ensuring food security through producing nutritious and healthy foods by reducing the use of pesticides. Increased rice yield, diversified farmer income, and reduced dependency on fertilizers are the short-term benefits of fish farming in rice fields. In conclusion, the integrated rice-fish farming approach demonstrates significant potential to enhance both ecological and societal well-being when compared to traditional rice monoculture practices.

2023-12-01T00:00:00Z