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Journal of Science (JSc)Number of Followers: 0
 Open Access journal ISSN (Online) 2602-9030
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- Nutritional composition of three commercially important brackish water
fish species recorded from Batticaloa Lagoon, Sri Lanka
Abstract: Fish is a high-quality animal-source food in the nourishment of millions worldwide. The most edible part of the fish is the muscle and which provides a proper balance of proximate and non-proximate nutrition and has a relatively low caloric value than other meats. The present study aimed to fill the gaps in the nutritional profile of three brackish water fishes (Arius maculatus, Mugil cephalus and Oreochromis niloticus) sourced from Batticaloa Lagoon, Sri Lanka. The study was conducted from November 2019 to February 2020 and fish were sampled from Kallady, Kattankudy and Arayampathy fish markets. The nutritional compositions such as moisture content, protein content, fat content and ash content of epaxial muscles of selected fishes were analyzed with standard methods. The moisture content was high among the fish muscles ranging from 56.73 ± 5.96% to 81.48 ± 2.52%. The protein content of A. maculatus, M. cephalus and O. niloticus muscles ranged as 15.36 ± 1.62%, 17.33 ± 1.96% and 13.7 ± 1.55% respectively. Amidst the selected fishes, O. niloticus is a lean fish (1.27 ± 0.35%) while A. maculatus (3.20 ± 0.59%) and M. cephalus (2.43 ± 0.37%) are low-fat fishes based on the muscle lipid content. The ash content of A. maculatus, M. cephalus and O. niloticus ranged from 1.22 ± 0.15% to 1.77 ± 0.45%, respectively. All the measured proximate parameters were significantly different (P-value < 0.05%) among the three fish species. The results of this study revealed that the A. maculatus contains the highest value of lipid and ash content while O. niloticus contains higher amount of moisture content. The M. cephalus can considered as a good source of animal protein compared to the other two fish species. Published on 2023-06-15 00:00:00
- Assess the prevalence and insecticide resistance of major dengue vectors
Aedes SP. in selected locations of Batticaloa District
Abstract: Dengue has become the major vector borne disease in Sri Lanka. Control of the vectors Ae.aegypti and Ae.albopictus through elimination of breeding habitats and application of insecticides are considered as the most effective ways to suppress the dengue epidemic. The mosquito larval survey was undertaken in three MOH areas such as Oddamavadi, Eravur, and Vantharumoolai, during the period in between January to March and September to October, 2020 in Batticaloa district. Five areas in each MOH area were selected randomly for the survey. Larval indices such as House index (HI), container index (CI) and Breteau index (BI) were calculated by using standard WHO guidelines in order to find the dengue epidemic risk. Resistance status of dengue vectors to four commonly used insecticides such as DDT, malathion, deltamethrin and carbamate were also assessed by using standard World Health Organization (WHO) procedures. Findings of the container survey and larval survey revealed that the three study locations are abundant with wet containers that are potential for the dengue mosquito breeding. There was a significant difference (p=0.001) in the abundance of indoor containers in all three locations whilst there is no significant difference (p=0.697) in the abundance of outdoor containers in all three locations. The results also indicated that both species can breed in urban, suburban, and rural areas. But Ae.albopictus prefers mostly rural and outdoor premises where there is dense vegetation. Ae.aegypti was the dominant species in all three locations. The larval indices have showed that Oddamavadi and Eravur were at high dengue epidemic risk and Vantharumoolai was at moderate risk. Results of insecticide bioassay revealed that both of the species were susceptible to deltamethrin and both were resistance to DDT and carbamate. It has also been found that both of the species were possibly resistance to malathion. From this result we can conclude that deltamethrin can be effectively used for space spraying programmes during the outbreak of Dengue in Sri Lanka. Published on 2023-06-15 00:00:00
- Ergasilid copepod infestation on some widely consumed fish species in
Valaichchenai Lagoon, Batticaloa District, Sri Lanka
Abstract: The present study was undertaken to find out the ergasilid copepod infestation on widely consumed fish species along three different locations in Valaichchenai lagoon during the Northeast monsoonal period from November 2019 to February 2020. The ergasilid copepod species namely Dermoergasilus amplectens, Ergasilus sieboldi, Ergasilus parvitergum and Sinergasilus major were recorded in the widely consumed fish species such as Etroplus suratensis, Mugil cephalus and Leiognathus fasciatus of Valaichchenai lagoon. The results revealed the prevalence and mean intensity in different gender of fish species for each ergasilid parasite in each location of the lagoon. Ergasilus parvitergum showed the maximum prevalence of 28.57%, 53.33% and 26.67% in each sampling locations of L1, L2 and L3 respectively. The highest mean intensity (14.5) was recorded in sampling location L1 for Ergasilus parvitergum which indicated that E. parvitergum is more adapted to their fish hosts when compared to other ergasilid copepod parasites found in Valaichchenai lagoon. Invasion of Sinergasilus major was recorded at polyhaline water (L1) in the present study. Spatial variation exists in the parasitic prevalence of Sinergasilus major (P = 0.00) and E. parvitergum (P=0.044) between sampling locations of the lagoon. However, spatial variations do not exist the in parasitic prevalence of Ergasilus sieboldi (P=0.124) and Dermoergasilus amplectens (P=0.749) between the sampling locations of the lagoon. Furthermore, the overall prevalence of parasites in the host fish values were 66.67% and 33.77% in females and males respectively which shows significant differences to each other. From the present study, it can be inferred that gender influences the degree of ergasilid parasitic infestation in fish during the northeast monsoonal period. Published on 2023-06-15 00:00:00
- Design and construction of a low cost coconut husk removing machine
Abstract: De-husking with traditional hand tools like machete or a spike depends on the skill of worker and involves training. Nowadays there is shortage of such skilled Workers. These affect the production rate of de-husking the coconut also more hazardous and harmful to user. To overcome the limitations and problems in the present methods, a manual or automated machine should be designed and fabricated. This research is to design and fabricate a low-cost coconut husk removing machine. The main purpose of this machine is to eliminate problems and limitations involved in de-husking process and to promote some small-scale industries and self-employment, especially for women. The machine with manual loading and unloading of coconuts will yield productivity higher than the existing process with less manpower. Also, the machine can accommodate different sizes of the coconut that are cultivated anywhere in Sri Lanka. Also, various experiments have been conducted on both dry and mature coconuts in order to determine the force required to de-husk the coconut. Test result and assessment of the present manual machine in both laboratory and field conditions are also reported. Safety aspects are incorporated. The unit can de-husk about 70 coconuts per hour compared with about 40 nuts per hour from a skilled worker using the spike method. Cost benefit analysis indicates that it should be commercially viable. Published on 2023-06-15 00:00:00
- Synthesis and characterization of eco-friendly bio lubricants from
plant-based oils
Abstract: Nowadays petroleum oil lubricants are most commonly use lubricant in motor vehicles and industrial machines. But those petroleum base lubricants create major problems to the marine and terrestrial environment. Researchers are trying to find new substances which are chemically modified for the substitution for petroleum base lubricant. Therefore, in this research four different types of bio lubricants were prepared by chemical modification of plant base oils such as Coconut oil, Palm oil, Neem oil and Waste palm oil. The bio lubricant was characterized using GC-MS analysis. And also Flash point, density at 150C, 400C and 1000C, viscosity at 400C and 1000C, viscosity index, acid value, yield percentage and cost of product of samples were analyzed. Published on 2023-06-15 00:00:00
- Characterization of micro-plastics in water and sediments in Batticaloa
lagoon at Kattankudy
Abstract: Micro-plastics (mps) are a globally ubiquitous contaminant and the occurrence and accumulation of mps in the aquatic environment is nowadays an undeniable fact. The present study intends to address morphological characterization and quantification of micro-plastics at Batticaloa lagoon near Kattankudy municipal dumping sites during the period of September 2019 to February 2020. A one-liter backet and Ekman grab sampler were utilized to collect water samples and sediments, respectively. Density separation was carried out using Nacl solution and all floating solids were subject to a wet per-oxidation method and observed under a stereomicroscope. All the recovered micro-plastics were sorted into categories based on the size (1 mm, 1-2 mm, 2-4 mm) shapes (film, fragment, filament, foam, pellet, microbeads) and colour (white, black, transparent and other colours). Kattankudy sample stations showed mps of 1638.83 ±71.69 items kg− 1 in sediment and 1028.33 ± 73.73 items per liter in surface water. Lagoon-shore sample site showed highest number of mps (surface water 691.10 ±28.50 items per liter, sediments 1033.00 ±28.80 items kg− 1) than lagoon sample sites. Overall abundance of mps was statistically significant (p<0.05; one-way Anova) among the study sites. Fragments were the most abundant particle shapes found within the sediments (~33%) and a greater number of films were overwhelmed in surface water (~47%) from both study sites. Less than 1 mm size fraction was the most common in sediments while somewhat larger sizes 2-4 mm was dominant in surface water. An assortment of colors was found in the mps gathered from both surface water and sediment among that in shore ~51% white colour and inside the lagoon ~27% were transparent. This study indicates evidence of micro-plastics pollution present in Kattankudy stations, which calls urgent precautionary measures to mitigate mps pollution. Further research is expected to address real impacts of these micro-contaminants on the lagoon environment in future. Published on 2023-06-15 00:00:00
- The minimum normalized cut value of tadpole graphs
Abstract: The Tadpole graph Tn,k is a Lollipop type graph obtained by joining a one vertex of cycle graph Cn to the end vertex of a path graph Pk The normalized cut is a measure of disassociation between two groups which computes the cut cost as a fraction of the total edge connections to all the vertices in the graph. This research focuses on deriving a formula to find the minimum normalized cut value of Tadpole graphs. Published on 2022-12-31 00:00:00
- Proximate and phytochemical analysis of selected wild edible green leafy
vegetables in Batticaloa
Abstract: Plant-derived natural products provide many novel bioactive molecules that are available in the market today as medicines or food. Wild Green Leafy Vegetables (WGLVs) have essential nutrients which are necessary for a healthy life. Three WGLVs such as Allmania nodiflora, Borreria hispida, and Rivea ornata were selected for the proximate and phytochemical analysis based on the market survey. Selected dry WGLVs were used to investigate proximate such as moisture, ash, fat, and fiber and phytochemicals such as alkaloids, flavonoids, tannins, steroids, terpenoids, phenolic compounds, and saponins analysis by using standard methods. The results were shown as follows: moisture 71.7±0.95- 80.3±2.84%, ash 8.84±0.69 - 11.05±0.21 %, fat 1.36±0.48 - 2.56±0.28 % and fiber 6.85±0.46 - 8.04±0.11 %. The qualitative screening of water, ethanol, and acetone extracts revealed that select WGLVs contained alkaloids, flavonoids, tannins, steroids, terpenoids, phenolic compounds, and saponin. Rivea ornata lacked quinones, while anthraquinones were only found in the water extract of Borreria hispida, and none of the three WGLVs were found to contain glycosides. Published on 2022-12-31 00:00:00
- Development and quality evaluation of oat (Avena sativa)
incorporated drinking yogurt
Abstract: Oat (Avena sativa) is a healthy cereal that is high in fiber and minerals. This research aimed to develop an oat powder incorporated drinking yogurt. 0.25, 0.50, and 1.0 g of oat powder per 100 ml of milk were selected as concentrations. Gelatin was not included due to the stabilizing ability of oat powder. To evaluate consumer preference and proximate analysis, oat concentration selected from a sensory evaluation was compared to a commercial drinking yogurt. For a period of 21 days, physicochemical (pH, Titratable acidity, and Total soluble solids) properties and microbiological quality were examined. The data was statistically analyzed using SSPS and SAS at a significance level of P<0.05. The most consumer-preferred oat concentration was 0.5 g oat powder per 100 ml of milk, with sensory properties identical to commercial drinking yogurt. The fat (3.43), protein (3.30), solids non-fat (26.08), and fiber (0.05) contents of the selected oat concentration were significantly higher than those of the commercial drinking yogurt. According to the yeast and mold count, oat drinking yogurt had a shelf life of 14 days after manufacturing. In conclusion, oat powder including drinking yogurt can be developed with better sensory properties which is competitive with commercial drinking yogurt. Published on 2022-12-31 00:00:00
- Determination of the antibacterial properties of crude extracts of
endophytic fungi isolated from Acrostichum aureum and Sonneratia alba
Abstract: Current issues associated with drug resistance and the adverse effects of synthetic agents have prompted researchers to focus on natural, medicinal agents such as mangroves and their associated fungal endophytes. The current study was developed to determine the antibacterial activities of crude extracts of endophytic fungi isolated from leaves, roots and stems of Acrostichum aureum, Karan koku in Sinhala and Sonneratia alba, Kirala in Sinhala. The endophytic fungal isolates were identified as Aspergillus niger, Aspergillus ochraceus, Aspergillus fumigatus, Aspergillus terreus, Penicillium citrium and Penicillium resticulosum and the respective crude extracts were generated using ethyl acetate. The crude extracts were subjected to antibiotic sensitivity tests (ABSTs) against two test organisms: Staphylococcus aureus (ATCC ®: 25923) and Escherichia coli (ATCC ®: 25922). The highest inhibitory action was exerted by Penicillium resticulosum against both the test organisms (E. coli: 15+0.05 mm; S. aureus 22+0.05 mm) which was the most abundantly identified endophyte in this study. The Minimum Inhibitory Concentration of the crude extracts was detected to be 1. 25 mg/ ml. However, the highest bactericidal action was noted from Penicillium citrinum. It is evident that the fungal endophytes isolated from mangrove plants possess antibacterial properties that can be used as a natural source for the generation of antimicrobial therapeutics. Published on 2022-12-31 00:00:00
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