ICAPS 2023

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Abundance and microplastic characterization found in the mud crab Scylla serrata inhabiting Negombo Lagoon, Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Dias, B. C. G.; Amarathunga, A. A. D.; De Silva, D. S. M.; Sivyer, D. B.; Maddumage, M. D. S. R.
Microplastics (MPs) are tiny plastic particles less than 5 mm in size. The danger imposed by MPs continues to rise in the world due to an increase in anthropological pollutants in the environment. The tremendous socioeconomic value and biodiversity of the lagoon have been threatened by a significant accumulation of plastics, particularly MPs. MPs have many negative impacts on the fauna. Herein, the high adsorption capability of MPs increases the toxicity of contaminants as well as oxidative stress that may lead to damaging cell membranes of fauna. Here, we report the investigation on the abundance of MPs in the digestive tract and gills of the mud crab species Scylla serrata, which is a prominent edible food source of humans. We collected fifty two (N = 52) individuals of mud crabs from three crab trapping sites in the Negombo Lagoon, Sri Lanka during November 2022 to March 2023. The gills and digestive tract of the crabs were extracted and digested in KOH, and subsequently the putative MPs were separated and imaged using a stereomicroscope (VWR VisiScope 360) for characterization. In the analysis, a total of 455 MP particles were detected in the crabs, out of which, 187 (41.10%) were in the gills and 268 (58.90%) were in the digestive tracts. The average MP abundance in the gills was 0.70 ± 0.52 items per gram, while that in the digestive tracts was 0.71 ± 0.52 items per gram. The most abundant shapes of MP particles were fibers in the gills (54.01%) and in the digestive tracts (85.07%) followed by fragments and films. Further, the prevailing colours of the MPs were blue, transparent, red, black, and purple. Herein, the digestive tract had the highest concentration of MPs in blue (47.38%), whereas the majority of the MPs found in the gills were transparent (51.8%). The range of MP sizes in the crabs was also determined. The most frequent size range in the gills and digestive tracts were 0.002-0.25 mm (39.5%), and 1.0-5.0 mm (48.8%) respectively. Despite the fact that the current study offered details on the presence of MPs in the gills and digestive tract of the mud crab species Scylla serrata inhabits in the Negombo Lagoon, it also serves as a benchmark for the quick detection of MPs in mud crabs in the lagoons of Sri Lanka.
Analyses of biometric growth parameters and feeding habits of Mugil cephalus (Flathead mullet): One of the economically important fish species collected from Negombo Lagoon
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Nimasha, N. T. P.; Perera, H. A. C. C.
Flathead mullet (Mugil cephalus) is found to be a potential candidate species in brackish water aquaculture due to its euryhaline nature, and it has ready markets for seeds as well as processed products. However, the lack of data on adult flathead mullets in the natural environment in Sri Lankan waters is the major constraint to study the biology of the species and management practices for fish resources. The present study was conducted to analyze the diet composition, length-weight relationship, and condition factor of M. cephalus belonging to the family Mugilidae collected from the Negombo lagoon, Sri Lanka. In fisheries science, the important condition factors are the growth, health state and feeding intensity. The sampling was done from August 2022 to March 2023. A total of 100 specimens were collected from the catches of artisanal fisheries from Negombo lagoon area. The total length and weight of fish were measured and varied in a range of 16.9 cm - 32.0 cm and 55.50 g - 291.70 g respectively. Length frequency distribution showed that the total length class 23 cm - 24 cm had the highest frequency of 100 samples. The FishBase reports length at first maturity as 30.0 cm and the percentage below 30 cm was observed as 97%. Results obtained showed a negative allometric growth pattern for this fish species (b<3, t-test, p< 0.05) with a significant linear relationship given by the equation; W = 0.0266TL2.690 (Log W = - 1.575 + 2.690 log TL (R2 = 0.951, n=100). Fulton’s condition factor (K) of males and females of M. cephalus was 1.0501 + 0.0359, and 1.0048 + 0.0123 respectively. Mean Fulton’s condition factor for immature mullets was lower than (0.9960 + 0.0724) that of the mature ones (1.0373 + 0.0735). Relative Gut Length (RGL) and Gastro Somatic Index (Ga.SI) were 1.52 – 3.18 and 2.012 – 3.874 respectively. The recorded mean RGL (2.442 + 0.146), confirmed that M. cephalus is omnivore species. The stomach content was analyzed using the frequency of occurrence method showed that algae (30.86%), sand particles (25.71%), and detritus (23.43%) as main food items. The food of animal origin consisted of annelids, insect parts and crustaceans. Most of the fish were one-fourth filled (1/4) at the time of capture. The immature individuals recorded from the Negombo lagoon area were 49 %. The present study reported the presence of synthetic debris such as nylon threads in the stomachs of flathead mullets revealing that the area is polluted. Therefore, more research into the effect of synthetic debris on the lagoon area is recommended. Continuous monitoring of fish landings is also recommended as immature individuals recorded were significant in the fish catch.
Analyses of biometric parameters, feeding, and fisheries aspects of Spotted Sardinella (Amblygaster sirm) occurring along the Negombo coastal waters of Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Wijesooriya, W. M. N. S.; Ratnayake, R. P. P.; Perera, H. A. C. C.
Amblygaster sirm is one of the major food fish in the small pelagic fishery in Sri Lanka. The study analyzed biometric parameters, feeding habits, and fisheries aspects of A. sirm in Negombo coastal waters. Two hundred A. sirm individuals were collected from the Negombo fish landing center and monthly interval from August 2022 to March 2023. The weight and total length of the collected fish ranged from 17.50 g - 109.00 g and 12.80 cm - 22.60 cm respectively. The lengthweight relationship (W=aLb) of males, females and pooled was W= 0.0029 TL 3.3546, W= 0.0035 TL 3.2819 and W= 0.0030 TL 3.3459. The significant deviation of the 'b' values from 3.0 indicates an allometric growth pattern for A. sirm in the coastal waters of Negombo (one-sample t-testp< 0.05). The Fulton’s condition factor (K) using the formula K = 100*W/TL, 0.9047 ± 0.1074, 0.94392 ± 0.08699 and 0.92331 ± 0.09995, for males, females and pooled respectively. The stomach-fullness of fish examined: were 40% empty, 15% one-fourth full, 12.5% half full, 27.5% three-fourth full, and 5% full stomach. Food and feeding analyses showed that ingested food includes 14.29% of phytoplankton including 1.53% of algae, 23.98% of mollusc larvae, 25.51% of crustacean larvae, 15.31% of fish eggs, 12.76% of arthropod appendages, 2.55% of synthetic fibers and 4.08% of unknown particles. According to the average Gastro Somatic Index, the highest and lowest feeding intensities using stomach fullness index were observed in the size class of 17.5 cm - 18.5 cm and 12.5 cm - 13.5 cm respectively. Their most preferred prey was crustacean larvae. The major vessel type used in fishing was Fiberglass Reinforced Plastic (OFRP) boats, operated within 15 - 20 fathom in depth. The small mesh drift gillnets with 31.75 mm and 38.1 mm mesh sizes was popular among the community. Of that, 38.1 mm mesh sizes are widely used. Synthetic materials in stomach content provide compelling evidence of the widespread contamination of marine ecosystems by human-made materials. The ingestion of these synthetic materials by fish poses a threat not only to their health but also to the overall ecological balance of marine habitats. Therefore, long term monitoring and research is recommended for the sustainable utilization of spotted sardinella fishery resources in Sri Lankan coastal waters.
Analysis of groundwater used in areas beyond the National Water Board distribution network in Ratnapura
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Karunasena K, . K. A. D. A.; de Silva, D. S. M.; Hakmanage, N. M.
Groundwater is the main source of drinking water in selected areas in Ratnapura where municipal water is not accessible. In a majority of households, it is consumed without any treatment. Waterborne diseases such as dysentery and typhoid fever may spread as a result of microbial pathogens. Chemical contaminants may also result in kidney-related issues. The present study was conducted to evaluate the quality of groundwater in three Grama Niladhari divisions around Ratnapura urban area. Amuwala, Kahengama South and Gonakumbura divisions were selected, and twenty wells were sampled from each division for three months as replicates. Measured parameters included total Coliforms, Escherichia coli, color, turbidity, pH, electrical conductivity, chloride, total alkalinity, total hardness, total iron, sulfate and total dissolved solids (TDS). Onesample t-test was performed at a 5% level of significance to assess the deviation of each parameter from Sri Lanka water quality standards. The results revealed that all water sources in the study were microbiologically contaminated throughout the sampling period. All of the physical and chemical water quality parameters were within the limits of Sri Lanka Standards (SLS) 614: 2013 except the pH level which was below the SLS requirement. The turbidity level was statistically significant at the SLS median value in Kahengama and Gonakumbura. Since the presence of E. coli bacteria indicates potential fecal contamination in the water, public awareness programmes are needed to educate consumers on the importance of consuming boiled water. The low pH issue can also be resolved by using pH adjusting water filters. The municipal distribution lines have to be extended further permitting access to disinfected potable water to a greater number of consumers.
Analysis of phytochemicals and antioxidant properties of Dendrophthoe falcata and Mangifera indica plant leaf extracts
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Karunarathna, M.G.T.N.; Kadigamuwa, C.C.
Dendrophthoe falcata, a common mistletoe plant, used in traditional medicine has not been adequately studied for the identification of compounds with biological activities. Phytochemical screenings allow the identification of chemical constituents with potential medicinal properties. These bioactive compounds hold promise as starting material for development of drugs. In Sri Lanka Dendrophthoe falcata is abundantly seen in Mangifera indica. The aim of the study is to quantify selected phytochemicals and the antioxidant properties in Dendrophthoe falcata and Mangifera indica (host tree) leaf extracts. The best extraction solvent was determined by cold extraction among methanol, ethanol, acetone, dichloromethane and water. Tannins content was determined using colorimetry with gallic acid as the standard. Alkaloids content was determined by a gravimetric method using acetic acid and ammonium hydroxide. In vitro DPPH (1, 1- diphenyl- 2- picryl-hydrazyl) radical scavenging activity, total phenolic content (TPC), total flavonoid content (TFC) and ferric reducing power assay (FRAP) were used to evaluate the antioxidant activity of plant leaf extracts. The TPC and TFC were determined by using FolinCiocâlteu colorimetric and aluminum chloride methods, respectively. The FRAP value was determined using colorimetry with ascorbic acid as the standard. Methanol had the highest extraction yield (25.20±4.34% w/w) compared to other solvents. Highest alkaloid content was observed in Dendrophthoe falcata leaf extract (DFLE) (31.32±2.59 % w/w). Highest tannin content (51.64±1.72 µg GAE/mL) was observed in Mangifera indica leaf extract (MILE). It was found that the DFLE demonstrated potent antioxidant activity compared to the half maximal inhibitory concentration of MILE calculated using DPPH assay (IC50 of DFLE 760.60±145.02µg/mL). DFLE had the highest TPC value (527.82±9.05 µg GAE/mL) and highest TFC value (399.70±13.95 µg CAE/mL). The maximum ferric reducing power was shown by DFLE (111.51±0.76 µg AAE/mL). The results suggested that the medicinal potential of DFLE is higher than MILE. Classes of compounds identified in Dendrophthoe falcata should be further studied to identify potentially beneficial compounds
Analysis of the interrelationship between weather parameters in Colombo area
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Samarasinghe, D. G. S. P.; Hewaarachchi, A. P.; Dissanayaka, D. M. P. V.
Colombo serves as the administrative, legal, and primary urban hub of Sri Lanka in terms of population. Its metropolitan vicinity houses around 5.6 million residents, with 752,993 within the Municipality. The city of Colombo is renowned for its tropical climate, characterized by consistently high average temperatures, substantial annual rainfall, and other meteorological factors. This study attempted to investigate the variations in the weather parameters and to model the interdependencies among those variables. The correlations of five weather parameters between January 2007 and May 2022 were analysed based on the monthly data collected from the Department of Meteorology in Colombo area. Rainfall, Minimum Relative Humidity, Maximum Relative Humidity, Wind Speed, and Temperature were considered in this study. Investigation of the correlation among various weather parameters holds paramount importance in understanding the intricate dynamics of Colombo's climate. A seasonal pattern was found in Minimum Relative Humidity, and high fluctuations were observed in Wind Speed and Rainfall out of the five weather parameters under study. Further, the study concluded that there is a moderate positive correlation (r = 0.5) between Rainfall and Minimum Relative Humidity and as well as between Rainfall and Maximum Relative Humidity (r = 0.7). A moderate negative relationship (r = -0.5) between Wind Speed and Maximum Relative Humidity is also found in this case study. In this research, vector autoregressive (VAR) models were employed to capture the relationships among weather parameters which indicated the presence of Granger Causality. According to the Granger Causality test it was found that Minimum Relative Humidity can be used in predicting the other four parameters i.e., Rainfall, Maximum Relative Humidity, Wind Speed, and Temperature. Maximum Relative Humidity can be used in predicting the Minimum Relative Humidity, Wind Speed, and Temperature. Also, Wind Speed can be used in predicting all other four weather parameters concerned in this study. It has been found that monthly average Temperature has the potential to serve as a predictive factor for all three of the weather parameters except Wind Speed under consideration in this investigation.
Analysis of the spatial relationship between land surface temperature and vegetation cover in Gampaha District, Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Amarasooriya, A. B. C. I.; Ratnayake, R. M. C. S.; De Silva, W.
Land Surface Temperature (LST) provides important information about the land surface’s physical properties and climate. Natural phenomena and anthropogenic activities, particularly urbanization, can alter LST. Besides, population increase, and urbanization are among the most widely reported drivers of vegetation cover change. As such, it is essential to investigate vegetation cover changes to identify vulnerable areas and implement sustainable management strategies to protect the environment. The present study evaluated the relationship between LST on vegetation change in the Gampaha district. Landsat 8 OLI /TIRS data of the study area from 2013 to 2015 were utilized to prepare vegetation maps and investigate LST. The thermal infrared bands of Landsat 8 were used to calculate the LST. Normalized Difference Vegetation Index (NDVI) was used to explore the vegetation change of the study areas. The result revealed that LST increased from 2013 to 2015. The maximum LST was reported from areas surrounding the Gampaha city (i.e., the maximum temperatures for 2013 and 2015 were 30.63°C and 35.02°C, respectively). The highest NDVI values reported for 2013 and 2015 were 0.62 and 0.52, respectively. Vegetation cover types of Gampaha district were classified into three categories based on the NDVI values (i.e., -0.1 to 0.2 non-vegetation, 0.2 to 0.3 sparse vegetation and 0.3 to 0.6 moderate vegetation). Interestingly, the current study revealed considerable changes in areas of vegetation cover classes over the study period. In 2013, the study area was found to be dominated by moderate vegetation (67.16 %) followed by sparse vegetation (27.92 %) and nonvegetation (4.92 %). However, between 2013 to 2015, the extent of moderate vegetation significantly declined from 67.16 % to 61.67 %, whereas sparse vegetation increased significantly from 27.92 % to 32.03 % (p < 0.01). Correlation analysis revealed a negative correlation between NDVI and LST, suggesting an increase in LST resulting in the decline of the vegetation cover change in Gampaha district. The results of this study may support urban planners, and respective authorities in making appropriate decisions to mitigate the environmental impacts of urban development activities in Gampaha district.
Antifungal activity of fresh fruit extract of Garcinia quaesita against Fusarium proliferatum causing crown rot disease in banana
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Lakmali, G.B.T.; Gunaratna, M.J.
Tropical fruits and vegetables are susceptible to several devastating post-harvest diseases. The crown rot disease of bananas is caused by Fusarium proliferatum, which causes a drastic decrease in consumer compliance and becomes a problem related to consumption. Though it can be controlled by approved natural or commercial fungicides, natural antifungal plant extracts are safer options due to their non-toxicity compared to synthetic fungicides. Garcinia quaesita is an endemic plant in Sri Lanka used as a spice and a medicinal plant. The poisoned food technique was used to determine the percentage inhibition of mycelial growth and the minimum inhibitory concentration of the plant extract on the test pathogens. Hence, the main objective of this study was to determine the antifungal activity of hydroethanolic extract (1:1 v/v) of fresh fruit of G. quaesita at different concentrations against F. proliferatum using the standard food poisoning method. The same procedure was carried out with a positive control (50% Captan) and a negative control (dimethyl sulfoxide). A round disk of 6 mm diameter was taken from a 7-day-old culture with grown mycelium and inoculated in the center of the PDA media plate with the treatments. The zone of inhibition (mm) and the percentage of growth inhibition were determined using three different concentrations of G. quaesita fruit extract (5000 ppm, 2000 ppm, 1000 ppm) with three replicates. All three concentrations of the plant extract significantly inhibited mycelial growth compared to the negative control. G. quaesita fruit showed 47.39% growth inhibition of F. proliferatum. The minimum inhibitory concentration for G. quaesita extract was 5000 ppm, which was significantly different as determined by Tukey's mean comparison test (p ≤ 0.05), with a zone of inhibition of 20 mm. The extract of G. quaesita shows promise as an alternative safe, ecofriendly, cheap, and easily degradable fungicide derived from plants. It also has great potential for providing new fungicides that are highly beneficial.
Antimicrobial activity of poly-herbal formula “Dasapanguwa” against several Gram positive bacteria and Gram negative bacteria
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Samaraweera, G. A.; Gunathilaka, V. H. N. M.; Perera, M. A. S. N.; Perera, P. D. V. M.; Wageesha, N. D. A.; Kadigamuwa, C. C.
The resistance of bacteria against available antibiotics has become a rising problem worldwide. Therefore, the discovery of alternatives using medicinal plants is widely studied. Although medicinal plants have been studied individually, the impact of herbal formulas was studied rarely. “Dasapanguwa” is a poly-herbal formula prepared as a decoction of 10 different plant parts to use in Ayurvedic medicine in Sri Lanka for colds, fever, and infectious diseases. Although the formula is used as a treatment for infectious diseases in Ayurvedic medicine in Sri Lanka, the antimicrobial action of this preparation was not scientifically assessed. The objective of the research was the determination of the antibacterial activity of the Dasapanguwa formula against Gram positive and Gram negative bacteria. Plant parts of Mollugo cerviana (L.) Ser., Solanum virginianum L., Solanum melongena L., Justicia adhatoda L., Rotheca serrata (L.) Steane & Mabb., Glycyrrhiza glabra L., Zingiber Officinale, Coscinium fenestratum (Gaertn.) Colebr., Piper nigrum L., and Coriandrum sativum L. were collected in dried form. Water extracts of decoction 1 (D1) (plant part: 5.0 g) and Decoction 2 (D2) (plants parts: 5.0 g ground into fine powder) were prepared by refluxing in 500.0 ml of water for two hours at 100 °C followed by freeze-drying. The antibacterial susceptibility test was performed by the Kirby-Bauer disc diffusion method against Gram positive bacteria (Staphylococcus aureus, Bacillus subtilis, and Enterococcus faecalis), and Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae). Antibiotic discs were prepared for each concentration of two decoctions (1.0 to 15.0 mg ml-1). Commercially available tetracycline (30 μg) and ceftriaxone (30 μg) were used as positive controls against Gram’s positive and Gram’s negative bacteria respectively according to the CLSI guideline. The diameter of the clear zones was measured. There were no inhibition zones against all the bacteria for tested concentrations of both decoctions compared to positive controls. Previous studies showed that the antibacterial activity of an herbal extract could depend on the plant, solvent, test pathogens, and concentrations. Furthermore, the activity could depend on the plant itself or the formula of poly-herbal. Therefore, it is recommended to further study the antibacterial activity of both decoctions for higher concentrations from 15 mg ml-1 against selected bacteria. Furthermore, the antibacterial activity could be studied for extracts prepared by different solvents including methanol and ethanol.
Antimicrobial and Antifungal Activities of Silver Nanoparticles Biosynthesized by Pothos scandens and Kaempferia galanga Aqueous Extracts
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Samadhi, K. G. A.; Kalansuriya, P.; Wijerathna, W. M. D. G. B.; Wasana, K. G. P.
In order to alleviate the clinical challenges associated with antibiotic use, there is an immediate need for innovative solutions. Utilizing nanotechnology-based antimicrobials represents a promising approach to enhance the effectiveness of natural products. Ayurvedic medicine has long relied on the utilization of Pothos scandens(family: Araceae, common name: climbing aroid, Sinhala name: Pota Wal, Tamil name: Annaparuva) and Kaempferia galanga (family: Araceae, common name: aromatic ginger, Sinhala name: Inguru Piyali, Tamil name: Kacholum). Leaves, barks, and gums of Kaempferia galanga are used to address a variety of microbial-related ailments. The objective of this study was to biosynthesize of PS-AgNPs and KG-AgNPs and conduct in vitro screening for antimicrobial properties. Pothos scandens bark pieces (10 g) and Kaempferia galanga rhizome (100 mg) derived aqueous crude extracts (PSA and KGA) was prepared under sonication (44 kHz, 40 ºC, 30 min). PSA and KGA coated AgNPs (PS-AgNPs and KG-AgNPs) were biosynthesized under different conditions i.e., homogenization, magnetic stirring, exposure to UV or sun light with loading different concentrations (2.5, 5, 7.5 mg/mL). Antimicrobial properties of crude extracts, PS-AgNPs and KG-AgNPs and uncoated AgNPs (UAgNPs) were screened in vitro (1 mg/per well) in triplicate, using agar well-diffusion method against standard microbial and fungal strains Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and Candida albicans (ATCC 90028). Gentamicin (intravenous solution at 40 mg/mL diluted to 0.4 mg/mL), 10 μg per well was used as the positive control against microbes and fluconazole (intravenous solution at 2 mg/mL diluted to 1 mg/mL), 25 μg per well was used as the positive control against fungal cultures. AgNPs were characterized using size distribution data, polydispersity index (PDI), zeta potential, FTIR, AFM and SEM imaging. SEM and AFM imaging revealed the presence of spherical PSAgNPs and KG-AgNPs with size ranges 50–300 nm. Inhibition zone diameter (IZD) of PSAgNPs against S. aureus was 15±0.816 mm, while it was zero for PSA. IZD for KG-AgNPs against S. aureus was 13±0.816 mm, while it was zero for KGA. PS-AgNPs (11±0 mm) showed antimicrobial activities against P. aeruginosa and against KG-AgNPs (15±0.816 mm) while it was zero for both PSA and KGA. IZD for PS-AgNPs and KG-AgNPs against C. albicans were 14±3.741 mm and 16±1.632 mm while it was zero for both PSA and KGA. PS-AgNPs, PSA, KGAgNPs and KGA did not exert any bioactivity against E. coli and U-AgNPs did not exert any bioactivity against the three microbial strains. The present study revealed that the novel PSAgNPs and KG-AgNPs formulation is a promising antimicrobial agent against P. aeruginosa and S. aureus
An application of time series techniques to forecast the Open market weekly average retail price of lime in Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Wickramarathne, R. A. S.; Wickramanayaka, M. P. A. T.; Mahanama, K. R. T. S.; Chandrasekara, N. V.
Limes are known for their acidic and tangy flavour and are commonly used in cooking, as a garnish, or to add flavour to drinks. The lime market in Sri Lanka is highly volatile, with prices fluctuating significantly on a weekly basis. In this research study, the main objective is to forecast the weekly lime price in Sri Lanka. Even though some research has been conducted on forecasting fruit prices in Sri Lanka, there is currently a lack of research on forecasting lime prices. The weekly price of lime from 1st week of January 2010 to 3rd week of February 2023 was considered for this study (632 observations). The first 600 observations were used as the training set and reserved data were used as the testing set. The time series plot of the weekly lime price of Sri Lanka indicates a slight upward trend and a non-constant variance with a seasonal pattern. The presence of a seasonal pattern motivated the development of a Seasonal Autoregressive Integrated Moving Average (SARIMA) model. When comparing Akaike’s Information Criterion (AIC), ARIMA(1,1,2)(0,1,1)[24] generated the minimum AIC value (-1.125469). Assumptions of autocorrelation and heteroscedasticity were not violated and the normality was violated. Although, the performance measures of ARIMA(1,1,2)(0,1,1)[24] were very low, ARIMA(1,1,2)(0,1,1)[24] was identified as the better model with mean absolute error of 40.799, mean absolute percentage error of 7.543, and root mean squared error of 49.793. The results obtained from this analysis would be helpful to mitigate price risks and uncertainties in the lime industry.
Assessment of contaminant levels of hazardous toxic metals and subsequent risk analysis in agricultural soil and selected comestibles within a region afflicted by CKDu in Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Perera, M. A. S. N.; Kadigamuwa, C. C.; Gunathilaka, V. H. N. M.; Samaraweera, G. A.; Perera, W. P. R. T.; Perera, P. L. R. A.; Liyanage, J. A.; Premaratne, W. A. P. J.
Agricultural commodities constitute a pivotal component of the human daily sustenance, yet they are susceptible to contamination by pernicious heavy metals, notably Hg, Cd, Pb, and As. Consequently, agricultural products represent a substantive source of apprehension for human well-being and health. This study aims to evaluate related risk indices of agricultural soils (n=25) and selected comestible grains, namely Oryza sativa (n=25), Vigna radiata (n=25), Vigna unguiculata (n=25), and Vigna unguiculata subsp. (n=25), within the endemic region of Nikawewa Grama Niladhari Division (GND) in North Western Province (NWP) and the reference region, Wewagedara GND in NWP where no evidence for Chronic Kidney Disease of unknown etiology (CKDu). The concentrations of metals in the collected samples were determined by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and based on that risk indices were calculated. The mean geo-accumulation index (Igeo) for four metals in soil was As - 0.82, Cd - 1.47, Cu - 0.91, and Pb 1.31. That indicates no anthropogenic activities related to As, Cd and Cu while Pb is responsible for moderate pollution in endemic area. Estimated Daily Intake (EDI) values for these heavy metals were calculated with respect to the all grains. EDI means of As and Pb in the endemic and the reference areas for all grain samples were within the Tolerable Daily Intake (TDI) set by United States Environmental Protection Agency (USEPA) (As-0.300 􀁐g/kg/day) and World Health Organization (WHO) (Pb-3.600 􀁐g/kg/day) while Cd (EDI in endemic area; Oryza sativa-6.385 􀁐g/kg/day, Vigna unguiculata-3.386 􀁐g/kg/day and Vigna unguiculata subsp.-3.866 􀁐g/kg/day) highly exceeded the tolerable weekly intake (TWI) of European Food Safety Authority (EFSA) (Cd-2.5 􀁐g/kg/week) in both areas. EDI of Cr in rice samples (1.138 􀁐g/kg/day) in endemic area exceeded the TDI set by EFSA (1.0 􀁐g/kg/day) and all other values of Cr were below the TDI in both areas. According to the USEPA (intolerable cancer risk (CR) - > 1 x 10-4) cancer risk exist for all these staple grains. Igeo of Pb in the soil, raising concerns about their bioavailability and uptake by the food crops and EDI were indicated the long-term consumption of these foods especially Oryza sativa poses a serious threat to human health. Implementing proper soil management practices, monitoring heavy metal levels in crops, and raising public awareness about safe consumption practices are crucial steps towards mitigating the risk of CKDu.
Assessment of heavy metals in oysters (Crassostrea cucullata), sediments, and water in selected locations of Negombo estuary
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Premananda, N. S. N. S.; Arachchige, Y. L. N. M.; Hemachandra, C. K.
Heavy metal contamination in aquatic environments is a matter of great concern due to its negative effects on both humans and other organisms. The present study was planned to evaluate the concentrations of selected heavy metals, cadmium (Cd), copper (Cu), lead (Pb), selenium (Se), and zinc (Zn), in oysters (Crassostrea cucullata), sediment (~1.4 m depth), and water (~0.5 cm depth). The samples were collected from four sites in the Negombo estuary in the dry season (March - April) of the year 2022. The selection of sampling locations was determined based on the presence of oysters. For each site, 20 oyster samples, 3 water samples, and 3 sediment samples were collected. The analysis was conducted following the protocols outlined in EPA (Environmental Protection Agency) methods 3052 for oysters and 3051A for sediments. This involved the use of microwave-assisted digestion and subsequently analyzing the samples with an inductively coupled plasma-mass spectrometer. A comparison was made between the average metal concentrations obtained from four study sites. The concentrations of heavy metals found in oysters were higher than the concentrations found in sediments and water at selected sites. Lead concentrations in oysters were safe for human consumption (21.52 ppb – 151.1 ppb), but zinc levels were higher than the (4834 ppb – 11538 ppb) WHO guidelines. The measured levels of copper (Cu), cadmium (Cd), and selenium (Se) were found to be within permissible limits. Metal concentrations in water were significantly lower than in sediments and oysters for all metals studied. There was no direct correlation observed between the metal levels in nearby sediments and water (The correlation coefficients for the metals are as follows: Cu (-0.466), Zn (0.180), Se (-0.174), Cd (0.036), and Pb (-0.445)). Metal distribution in water inlets of the estuary did not show a clear pattern. Water consistently had lower metal concentrations compared to sediments and oysters. The present study suggests several avenues for future research. Long-term monitoring may reveal temporal variations in metal concentrations, while source identification studies can trace the origin of pollutants. Investigating bioaccumulation factors in oysters and their ecological impacts on the ecosystem is crucial. Developing remediation strategies and conducting human health risk assessments are necessary for mitigating contamination effects. Pursuing these research directions can lead to improved understanding and protection of the estuarine environment and human health.
Assessment of level of public knowledge, attitude, and perception towards sustainable mangrove forest conservation: a case study from Negombo region, Sri Lanka
(Assessment of level of public knowledge, attitude, and perception towards sustainable mangrove forest conservation: a case study from Negombo region, Sri Lanka, 2023) Wickramasingha, W. S. B.; Perera, W. W. A. M. R.; Kodithuwakku, K. C.; De Silva, K. V. N. T.; Karunarathne, D. M. S. D.
Mangroves have been an essential vegetative component not only in sustaining the balance of ecosystems but also in providing significant socio-economic benefits to the local communities such as fish, timber, and tourism opportunities to the local communities. Quantifying knowledge, attitudes, and perception (KAP) supports sustainable mangrove conservation by informing conservation efforts to address local needs and priorities and monitoring interventions' effectiveness over time. Thus, this study aims to determine the level of knowledge, attitudes, and perceptions of the public toward sustainable mangrove forest conservation in the Negombo region, Sri Lanka. Prior to data collection, a pilot study was conducted in the study area with 40 respondents and Cronbach's alpha (α = 0.819) reliability test was followed to test the reliability of the data. Data were collected via face-to-face interviews with randomly selected 395 respondents living near and around the northern region of the Negombo lagoon, which involved 8 Grama Niladhari Divisions. 51.39% of the individuals were male, while the remaining 48.61% were female, reflecting a commitment to gender equality. A Likert scale and correlation analyses were implemented using SPSS version 26 software to determine the community's knowledge, attitude, and perception (1-lowest and 5-highest). The finding shows that the level of knowledge of the community on the importance of sustaining mangrove forests was high from 3.92 to 4.72, the level of attitude was between 3.2 to 4.88, and the perception components from 4.47 to 4.83. There were significant gender differences in both attitude and perception toward mangrove forest conservation, with the female respondents achieving better scores than the male respondents, although there was no significant difference in their knowledge levels. Also, about 96.2% of respondents agree that the loss of mangroves will have negative impacts on the environment and the economics of the livelihood. Furthermore, most respondents believed that chemical pollution, illegal clearing, and development activities have a significant impact on the degradation of mangroves in the area. The correlation test showed that there was a strong positive correlation between knowledge and attitude (r = 0.901, p < 0.001), knowledge and perception (r = 0.795, p <0.001), and attitude and perception (r = 0.864, p < 0.001) respectively. They suggest that the most effective approach for preserving this ecosystem's survival is to engage in mangrove replanting through proper scientific monitoring, while also recommending the rectification of policy deficiencies and the execution of comprehensive strategies for mangrove conservation. The findings from this study may provide valuable information for future research, as well as assist government and stakeholders in enhancing the effectiveness of campaigns and programs focused on the sustainable management of mangrove forests.
Assessment of litter and microplastic pollution in the water and sediment of Hirikatuoya stream, within the Walawe River basin, Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Lahiru, A. A. S.; Amarathunga, A. A. D.; Malavipathirana, S.; De Silva, D. S. M.; Sivyer, D. B.
Rapid urbanization and mismanagement have led to a surge in plastic pollution in crucial aquatic ecosystems globally therefore accumulation of debris in aquatic ecosystems is rapidly increasing and they are becoming ultimate sinks for the contaminants. This results in a long-term and widespread threat causing a great challenge for remediation. Poor disposal practices and littering behavior of communities have resulted in considerable quantities of litter in river banks and streams affecting their aesthetic appeal and living beings. This study was conducted to understand the status of litter and microplastic contamination at selected locations in Hirikatuoya stream, a remote stream outside the urban environment in the Rathnapura district, Sri Lanka. The percentage of plastic in litter and the percentages of microplastic particles (based on colour and morphotypes) in water and sediments were estimated, and the corresponding polymer types were also identified. Three samples of water were collected from each of the nine locations along the stream from September to October 2022. In the sampling process, the samples were filtered through a 150 μm mesh. Sediment samples were collected from the shoreline of the stream at each location using a stainless-steel scoop covering 30 cm2 of surface area and 2-3 cm depth. Lowdensity particles in the samples were separated by density separation and organic matter in the sample was removed by digestion. Whatman GF/C glass microfiber filter papers of a pore size of 1.2 μm were used for sample filtration. Microscopic imaging was done using a staining method. The ATR-FTIR analysis was performed to identify the polymer type of plastic particle in water samples. The most frequently observed colour for microplastic particles in water and sediments were white (26.87%) and colourless (40.20%), respectively. Based on morphotype, fragments were more abundant in both water (49.62%) and in sediments (59.79%) compared to other morphotypes. The highest microplastic abundance in water (69±22, 60±29, 61±26 items 100 m- 3) and highest abundance of microplastics in sediment (15±5.92 items/kg (top), 7±3.28 items/kg (bottom)) were observed in more human and tourist activity locations. According to the ATRFTIR analysis, polypropylene was the most abundant polymer type in plastic litter (25%). In water polypropylene was the most dominant microplastics (38.10%), followed by low-density polyethylene (14.29%) and polyethylene terephthalate (9.52%). Polypropylene was the dominant microplastics in sediments (32.2%), followed by thermoplastic vulcanizates (22.5%), highdensity polyethylene (19.3%). Accordingly, it can be concluded that the Hirikatuoya stream, which is in a remote area, is contaminated with microplastics. There are potential environmental and health risks to the aquatic biota in the stream and the neighboring communities. Further investigations are required to understand the effect on aquatic animals.
Assessment of phenolics in selected Phalaenopsis cult
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Tikirikumari, J.A.T.; Thathsarani, Y.K.D.D.; Senanayake, R.A.S.P.
Orchidaceae ranks as the second-largest family of flowering plants. Phalaenopsis species belong to the family Orchidaceae are highly prevalent and commercially significant. Because of the floricultural significance, range of cultivars and hybrids resulted by performing crosses using parents with desirable characters, beneficial to the floriculture industry. Phytochemicals play an important role in plant defense mechanisms and dispersal mechanisms. They are unique to specific plants and parts of plants and usually increase in abundance during stressful events. The main groups of phenolic compounds include flavonoids, phenolic acids, tannins, and lignan compounds. Flavonoids are naturally occurring compounds and possess distinctive biological activity with high antioxidant capability. This study was conducted to quantify the total phenolic content, and total flavonoid content of six different Phalaenopsis cultivars to select parental materials with promising characters which are essential for plants to cope with stress in relation to plant physiology. Six self-pollinated Phalaenopsis cultivars were selected based on the color, shape, and overall attractiveness of the flowers to represent different colors and pigmentation patterns and maintained in the greenhouse. Total phenolic content and flavonoid content were quantified using methanolic extracts of known weight of leaves and roots following the standard methods used in the phytochemical analysis. According to the obtained data, Purple-colored Phalaenopsis cv. Queen Beer ‘Mantefon’ root extract recorded the highest flavonoid content (5.50± 0.01 mg QE g-1 DW) and yellow-colored Phalaenopsis cv. Golden Sands ‘Canary’ leaf extract recorded the highest phenolic content (335.77± 0.02 mg GAE g-1 DW). The highest phenolic and flavonoid content in a plant could contribute for developing the potential for high antioxidant activity. Therefore, these cultivars which have the most favorable characteristics than other studied cultivars can be used as parental material in future quality improvement and plant breeding programs.
Assessment of the antioxidant, anti-diabetic, and anti-obesity activities of a Sri Lankan "spice" mixture at different storage conditions used for treating obesity
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Jayawantha, M. L. D. C.; Manuha, M. I.; Paranagama, P. A.
Obesity, diabetes, and hypertension have become prevalent health issues in Asian countries, affecting individuals at young age. Systemic oxidative stress and adipose tissue contribute significantly to the development of insulin resistance associated with obesity and type II diabetes. Due to the possible toxicity and carcinogenicity of synthetic antioxidants, there is a global need to discover safe antioxidants to use as food additives. To address these concerns, clinical trials were conducted in Sri Lanka using a spice mixture consisting of commonly used spices in Sri Lankan cuisine: Cinnamomum zeylanicum, Cuminum cyminum, Piper nigrum, Murraya koenigii, and Allium sativum. This study aimed to evaluate the antioxidant, anti-obesity, and anti-diabetic potential of a methanol extract derived from this Sri Lankan spice mixture, as well as to evaluate the above activity properties of five glass bottle samples stored at different storage conditions: the positive control (STD), the initial spice mixture sample (INT), the sample after three months at room temperature (RT), the sample after three months in a dark environment (BLK), and the sample after three months in a refrigerator (COOL). The IC50 value of the methanol extract of INT demonstrated significant antioxidant activity (0.08 ± 0.03x10-2 mg/mL, p < 0.05) in the DPPH assay compared to the positive control, BHT (0.07 ± 0.05x10-2 mg/mL). Similarly, the lower IC50 value of INT indicated higher antioxidant activity (0.17 ± 0.14x10-1 mg/mL) in the ABTS assay when compared to the positive control BHT (0.36 ± 0.15x10-1 mg/mL). In both assays, the IC50 values followed the order of INT < COOL < BLK < RT, signifying decreasing antioxidant activity in the same order. The methanol extract samples (1.0 mg/mL) in the FRAP assay showed increasing relative % reducing power in the order of RT < BLK < COOL < INT, with values of 30.37%, 32.14%, 32.74%, and 37.05%, respectively, which was lower compared to the positive control (BHT). The α-amylase inhibition assay revealed that the IC50 of the methanol extract of the INT was 0.29 ± 0.21x10-1 mg/mL compared to the positive control Acarbose (IC50, 0.06 ± 0.02x10-1 mg/ml). The IC50 of the methanol extract of INT in the antilipase assay was 0.14 ± 0.05x10-1 mg/mL, while the positive control (Orlistat) had an IC50 of 0.09 ± 0.01x10-1 mg/mL. These results revealed that the IC50 value increased in the order of INT < COOL < BLK < RT, when each glass bottle sample was stored after three months according to their distinct conditions, suggesting a negative correlation between assay activity with light intensity, temperature, and storage time. Overall, the study concluded that the spice mixture used for reducing obesity exhibits significant antioxidant potential. Additionally, the results from the anti-lipase and α-amylase inhibition assays suggest that the bioactive constituents present in the methanol extract have the potential to inhibit lipase and α-amylase enzymes, providing antiobesity and anti-diabetic benefits.
Assessment of water quality and pollution state using selected physicochemical parameters and bioindicators in “Modi canal” Galle
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Perera, U. V. D. H.; Guruge, W. A. H. P.
This study was carried out to assess the water quality and pollution status using selected physicochemical and biological parameters in “Modi Canal” at Galle. Water samples were collected from five different sites for assessing selected physicochemical parameters. Sediment samples by Ekman grab and filtered water samples by plankton nets were also collected to assess water quality using macroinvertebrates, zooplanktons, and phytoplanktons. Shannon Wiener Diversity Index (SWDI) and Pollution Tolerant Index (PTI) were calculated for macroinvertebrates, zooplanktons and phytoplanktons according to the standard manual published by the United States Environmental Protection Agency (USEPA). During the study period, range of mean values of physicochemical parameters in the five sampling sites were temperature: 27.5-28.90C, pH: 6.97-7.29, conductivity: 0.14 - 4.92 mS, salinity: 0.05-1.94 ppt, dissolved oxygen: 1.39-5.98 mg/L, biological oxygen demand: 0.34-1.14 mg/L, chemical oxygen demand 4.89-29.20 mg/L, alkalinity: 0.001- 0.004 mg/L, nitrate: 0.595-1.48 mg/L, phosphate: 0.437-2.867 mg/L. All the selected physicochemical parameters in selected five sites were significantly different from each other (p<0.05: One-way ANOVA) during the study period. Considering the biological parameters, most of the macroinvertebrates identified within the canal were pollution-tolerant species such as chironomid larvae and aquatic worms. The calculated SWDI value for macroinvertebrates ranged from 1.30 to 1.87 and the PTI value ranged from 10.7 to 9.2. The SWDI values for zooplanktons ranged from 0.79 to 1.13 among the sites. Group Cladocera was recorded prominently in most sites. Among phytoplanktons, Spirogyra sp. And Cylindrospermum sp. were recorded as mostly found species and the SWDI value for phytoplanktons ranged from 0.83 to 1.31 among the sites. No significant differences of abundance values were observed among sites for macroinvertebrates, zooplanktons, and phytoplanktons. The present study concludes the “Modi Canal” at Galle as heavily polluted.
Atmospheric chemical composition of bulk precipitation of selected areas of Galle District.
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Amunugama, H. M. L. V.; Deeyamulla, M. P.
The quality of the atmosphere refers to its composition and the presence of pollutants, while precipitation can have direct effects on the quality of the atmosphere. Both wet and dry deposition contribute to the removal of pollutants and particles from the atmosphere. Therefore, it is very important to collect data on the chemical composition of the atmosphere to identify air pollution and its causes and to control air pollution. This study focuses on the chemical composition of precipitation in selected areas of Galle district, one of the most urbanized districts in the southern province. Wet precipitation samples were collected from three industrial sites, Unawatuna, Bataduwa, Koggala and the Sinharaja rainforest area of Lankagama, the country's last viable area of primary tropical rainforest. Wet precipitation samples were collected from September 2022 to February 2023, which covers the South-West monsoon, Second inter-monsoon, and North-East monsoon seasons and a total of 40 samples were analysed for pH, conductivity, Na+, K+, Mg2+, Ca2+, NH4 +, Cl-, F-, Br-, SO4 2-, NO3 -, Cu, Pb, Ni, Cd, Fe, Al, Zn, C, and Mn. Based on VWM (Volume Weighted Mean) pH values Unawatuna (6.95±0.6), Bataduwa (6.69±0.8) and Koggala (6.8±0.3) sites had slightly alkaline pH values, while the control site Lankagama-Sinharaja (5.73±0.02) had slightly acidic pH. The volume-weighted average concentrations of major ionic species in the precipitation samples from the industrial sites were in the order Na+ > Cl- > SO4 2- > Ca2+ > NO3 - > NH4 + > K+ > Mg2+ > Br- > F-, while the control site followed the order of Na+ > Cl- > SO4 2- > Ca2+ > NH4 + > K+ > NO3 - > Mg2+ > F- > Br-. The neutralization factor (NF) for Na+ ions indicates that higher Na+ concentrations contribute to the neutralization of acidic components at the Unawatuna, Koggala and Lankagama sites. When considering the marine contribution, The Enrichment Factors (EF) calculated for SO4 2-/Na+, Ca2+/Na+ and Mg2+/Na+ ratios were higher than the reference value, suggesting that several anthropogenic sources other than marine may be contributing. Among metallic constituents, Zn and Al concentration were higher at all sites except the Koggala site, which had higher Fe content. Pb and Ni concentrations were below the detection limit of ICP-MS at all sampling sites. This study confirmed the relationship between atmospheric chemical composition and nearby anthropogenic and natural sources, as well as the indirect relationship between rainwater analysis and air quality in a given region. Furthermore, the precipitation data from Sinharaja demonstrates the absence of pollution, further solidifying its reliability as a backdrop.
An attempt to establish a cutoff value for peripheral blood hematopoietic progenitor cell count to predict the viable CD34 count in multiple myeloma patients undergoing autologous peripheral blood stem cell transplantation
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Hewapathirana, T. D.; Perera, T. C.; Tudugala, R.; Suresh, S.; Kottahachchi, D. U.
Multiple myeloma (MM) is a common hematological malignancy characterized by the proliferation of abnormal plasma cells in the bone marrow, leading to immune dysfunction and bone damage. Autologous peripheral blood stem cell transplantation (aPBSCT) is a pivotal treatment for MM, extending survival rates. The success of aPBSCT relies on the composition of the mobilized peripheral blood cells, particularly the hematopoietic progenitor cells in peripheral blood (HPC_PB). In aPBSCT, viable CD34 cell count (V_CD34) which is enumerated by the flow cytometer (FC) is used to calculate the minimum stem cell yield required for a successful transplantation. Therefore, detecting the optimal HPC_PB count in relation to V_CD34 is crucial for enhancing the effectiveness of aPBSCT and also for the proper management of MM patients. To establish a cutoff value for HPC_PB using an automated hematology analyzer (AHA) as a predictor for V_CD34 in the peripheral blood of MM patients undergoing aPBSCT. This initiative aims to replace or supplement the flow cytometry (FC) facility with AHA, as AHA provides a cost-effective, user-friendly, faster, and more accessible method for assessing cellular profiles during PBSCT. This transition addresses the limitations of the FC technique, which encompass high expenses, complexity, the demand for specialized personnel, substantial sample sizes, timeintensive procedures, and restricted availability. MM patients representing males (n=23) and females (n=22) at the age of 40-65 years, admitted to the Bone Marrow Transplant Unit (BMTU) in Apeksha Hospital, Maharagama, Sri Lanka were selected for the study (n=45). The ninth day from the mobilization of the bone marrow cells was considered as the day of harvesting. The Sysmax-1000 AHA was used to enumerate HPC_PB and, V_CD34_PB was enumerated by flow cytometer (FC) BDACS Lytic TM using already collected samples for routine testing. First, the data were separately tested for normalization, followed by correlation bivariate analysis and, Receiver Operating Characteristic (ROC) curve analysis to establish relationships and cutoff values for HPC_PB respectively. In the ROC analysis, the two groups of V_CD34_PB were defined as; Group 1 =90 cells/µL.In the statistical analysis, the HPC_PB_AHA showed normal distribution while V_CD34_PB_FC did not follow it. HPC_PB possessed a significant (p=0.000) strong positive Spearman bivariate correlation (r = 0.930) with the V_CD34_PB. The cutoff value obtained for the HPC_PB is 89 cells/µL, at V_CD34_PB of 90 cells/µL with sensitivity (97.1%), specificity (99.9%), and area under the curve of 0.978 with statistically significant (p=0.022