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Developing a Drumstick (Moringa Oleifera) Incorporated Functional Drinking Yoghurt
(University of Peradeniya , Sri Lanka, 2014-07-04) Weerasinghe, L. T. K.; Madhujith, T.; Sarananda, K. H.
Moringa oleifera leaves have been reported to be a rich source of β-carotene, protein, vitamin C, calcium and potassium. In addition, it is reported that Moringa leaves possess bioactives that bring about a myriad of health benefits. Incorporating Moringa into yoghurt can increase the health benefits. Moringa oleifera leaf samples, sugar and gelatin were obtained from local market. Liquid milk was purchased from University of Peradeniya and the starter culture was obtained from Veterinary Research Institute (VRI), Gannoruwa. Moringa leaf powder (DMLP) was prepared by drying, grinding and sieving of Moringa leaves. The particle size of DMLP was less than 125 μm. Set yoghurt was prepared incorporating varying quantities of DMLP [0.5, 1, 2 and 4%, (w/w)] to the yoghurt mixture. Stirred yoghurt was prepared following the same procedure with the exception of adding extra sugar or water. The so prepared set and drinking yoghurt samples were evaluated for sensory attributes to select the best concentration of DMLP for drinking and stirred yoghurts. According to the paired preference test, drinking yoghurt containing 1% DMLP was the most preferred yoghurt formulation, thus set yoghurt was dropped from the rest of the study. It was observed that 1% DMLP was the most preferred formulation for drinking yoghurt. Furthermore, the selection of the best flavouring agent for set and drinking yoghurts was also carried out through the sensory analysis. Mango flavour was the most preferred flavouring agent for 1% DMLP added drinking yoghurt. Proximate analysis of the best set and drinking yoghurts was performed following standard AOAC methods. Proximate analysis revealed that drinking yoghurt containing 1% DMLP contained 74.28 ± 0.03% moisture, 25.72 ± 0.03% dry matter, 3.91 ± 0.655% ash (on dry weight basis) and 1066.91 mg/100g ± 28.39 calcium. The titratable acidity, TSS and pH of yoghurt were 0.82 ± 0.010%, 21.97 ± 0.06% and 4.60 ± 0.01, respectively. It is concluded that Moringa dry leaf powder, which carries many bioactive properties can be incorporated into drinking yoghurt without affecting the sensory attributes.
Effect of Substituting Calf Milk Replacer with Porcine Whole Blood on the Growth and Performance of Bull Calves
(University of Peradeniya , Sri Lanka, 2014-07-04) Wijetunge, W. M. G. I. S. L.; Himali, S. M. C.; Senavirathna, N. G.; Cyril, H. W.; Vidanarachchi, J. K.; Randheera, C. S.
Most of the calves in the commercial farms are fed with milk replacer during their liquid feeding period. As an alternative low cost protein ingredient, porcine whole blood was evaluated by substituting as a possible calf milk replacer. Twelve (12) male Holstein-Friesian calves (weight 40±5 kg and 21±10-day old) were used for the experiment. The study period was 42 days. After adaptation period of seven days, calves were assigned randomly for three groups. The control group of calves was fed with100% calf milk replacer, while the other two groups were fed with milk replacer substituted with 10% whole blood and 15% whole blood. The animals were fed with 4 L and 3 L of milk replacer/milk replacer containing whole blood per day in the first month and for the rest of the research period respectively. All other management practices were performed similarly for all the calves used in the experiment. Daily intakes, rectal emperature and fecal consistencies of each animal were recorded. Body weight, heart girth, body length, skinfold thickness were measured weekly. Daily intake of milk replacer/milk replacer substituted with blood was the same for all calves throughout the experiment period. Body weight gain/week, heart girth, body length, skinfold thickness were analyzed as repeated measures ANOVA using the Mixed Procedure of SAS. There was no significant difference (p>0.05) in the body weight gain (2.5±0.6kg/week), heart girth (85±5 cm), body length (68±5 cm) and skinfold thickness (1.090±0.2cm), concentrate intake (3±1.9 kg/week) among the treatments. The result of this experiment demonstrates that 10% and 15% of calf milk replacer can be successfully substituted by porcine whole blood. The findings suggest the possibility of using whole blood of pigs obtained as a slaughterhouse by-product to reduce the cost of feed in rearing calves.
Spatial variability of organic carbon desnity in cashew cultivated red latosol soils of Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11) Wickramasinghe, W.M.K.M.; Karunaratne, S.B.; Gajanayake, B.; Abeysinghe, D.C.
Soils contribute to regulate major biochemical cycles and in case of carbon (C) cycle it plays a vital role. In fact soil act as the largest terrestrial pool of C. Therefore, much attention is given to quantification of below ground C stocks or densities and uses this information for long term monitoring of C sequestration potential. In this study, an attempt was made to quantify the spatial variability and subsequently map (predict) the soil organic carbon (SOC) densities under cashew grown in Red Latosol soils. For this, a sub set of 22 ha was selected from the cashew seed garden in Elluwankulama, Puttalam district managed by Sri Lanka Cashew Corporation. A design- based sampling scheme namely stratified random sampling was adopted in this study. The stratification was carried out using compact geographic stratification (based on coordinates) with the aid of k-means clustering algorithm and the study area was divided into five strata. Total of 100 sampling locations were sampled where 20 sampling locations were allocated to each stratum. For all sampled locations, SOC density was calculated. In calculating of SOC density, a pedotransfer function (PTF) was used to predict the bulk density for sampling locations which did not measure bulk density in the field. Geostatistical approach was used to create higher resolution digital soil map of SOC density across the study site. Both PTF predicted bulk density values and geostatistical models were validated and statistically assessed using mean error (ME) and root mean square error (RMSE) indices. Summary statistics revealed that mean SOC %, bulk density and SOC density reported as 0.96 % (±0.21), 1.43 gcm-3 (±0.03) and 4.12 (±0.82), respectively. Results revealed that the bulk density values predicted by PTF reported ME of 0.0041 gcm-3 and RMSE of 0.0044 gcm-3 values for Red Latosols in the study site. The optimum spatial model for SOC density was identified as spherical model which reported lowest RMSE (0.769 ) and ME (0.00084 ) values. The nugget-to-sill ratio showed a moderate spatial dependence for SOC density (0.43). Furthermore, results revealed that spatial auto-correlation (range parameter) of SOC density goes up to 82 m. This indicates that in future sampling of Red Latosols in order to characterize the spatial variability of SOC density, sampling interval should be maintained within 82 m. Predicted SOC density over the study area reported a mean value of 4.14 (±0.34) while 3.95 and 4.34 for quantiles one and third, respectively. Results further revealed that majority of the land extent (13.4 ha) in the study site reported SOC density in between 4.0 to 4.5 . The information generated in this study could be useful in national carbon accounting programs, carbon credit programs and for site specific fertilizer application.
Awareness and distribution of Invasive alien species (ias) of flora in galigamuwa area
(University of Peradeniya, Sri Lanka, 2015-11-06) Warunasinghe,W.A.A.I.
Biological invasions happen either deliberately or accidentally and are considered as serious threats to the biodiversity and its irreversible impact to the biodiversity is second only to the habitat loss. Thirty common IAS of plants were selected and the study inquired whether the local people were well aware about IAS of flora and if so, whether these species have badly influenced the environment and farming activities and its distribution in Galigamuwa area. Primary data were collected through a pretested self-administered questionnaire and 65 households were selected by using Multi stage random sampling technique. Analysis was carried out based on descriptive statistics together with graphical interpretation. According to the depicted results, all the respondents (100%) were aware about IAS of flora. Majority of the respondents (46%) educated through newspapers. Only few respondents (6%) were aware about Guinea grass (Panicum maximum), one of the prominent IAS of flora in Sri Lanka. Moreover, very few respondents were aware about Rila Thana (Pennisetum polystachion) 2% , Wal Sudda (Austroeupatorium inulifolium) 12%, Mist flower (Ageratina riparia) 3%, Gal Goraka (Clusia rosea) 7%, welvet tree (Miconia calvescens) 6%, Kikiyu grass (Pennisetum clandestinum) 2%, Parthenium (Parthenium hysterophorus) 12%, Kattakumanjal (Myroxylon balsamum) 8%, Yellow cestrum (Cestrum aurantiacum) 3%, Blue stars (Aristea ecklonii) 2% and Arunadevi (Sphagneticola trilobata) 2%. According to the depicted results, respondents have not observed Kikiyu grass (Pennisetum clandestinum) and Rila Thana (Pennisetum polystachion) in their surroundings. Moreover, no respondents (0%) were aware about Gorse (Ulex europaes). Results revealed that, majority of the respondents have seen water hyacinth (Eichhornia crassipes) 69%, salvinia (Salvinia molesta) 54%, Katu pathok (Opuntia dilenii) 57%, Katakalu Bovitiya (Melastoma hirtum) 60%, Wathupalu (Mikania micrantha) 72%, Mahogani (Swietenia macrophylla) 74%, Lantana (Lantana camara) 55%, Podisingnomaran 62% in their surrounding environments. While 69% of the respondents were aware about pinus (Pinus caribaena), only 25% of them have seen pinus in their surroundings. Of the sample, majority of the respondents were aware about Ginikuuru Gas (Alstonia macrophylla) 51%, Wild sunflower (Tithonia diversifolia) 58%, Para (Dillenia suffruticosa) 58% and Yoda nidikumba (Mimosa pigra). Very few of the respondents were aware about Katu Andara (Prospis juliflora) 35%, cuscuta (Cuscuta compestris) 40%, Kadadasi Mal (Antigonon leptopus) and Cheena Pera (Psidium littorale) 25%. Of the sample, majority of the respondents (58%) were facing difficulties in their day to day lives due to IAS of flora and most of them (52%) try to control these plants. Majority of the respondents (43%) have observed the reduction of native plant species due to IAS of flora and 37% of the respondents do not have clear idea about the adverse impacts of IAS of flora. According to the results, 45% of the respondents have reported that IAS flora have badly affected to their aquatic environments.
Selenium in rice (Oryza sativa) from different geographic and climatic regions of Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Diyabalanage, S.; Navarathna, T.; Chandrajith, R.
Rice is the main staple food in Sri Lanka as in many other Asian countries. It has been identified that people who consume rice as a staple food are inevitably exposed to significant amounts of different trace elements. Among these trace elements, selenium (Se) is one of the least known, but essential element for both humans and animals. Deficiency of Se can increase the susceptibility of the kidney’s to oxidative damage, but Se becomes toxic to humans when the intake exceeds 900 μg/kg per day. Availability of Se and other bio-important trace elements in rice from Wet Zone (WZ), Dry Zone (DZ) and Intermediate Zone (IZ) were investigated in this study. Concentrations of 19 trace elements in 200 rice samples, including improved (n=188) and traditional rice varieties (n=12) were measured with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) after microwave aided acid digestion. The Se contents in improved rice varieties ranged from 0.03 to 261 μg/kg with mean values of 35.4 μg/kg, 42.8 μg/kg and 22.1 μg/kg for WZ, DZ and IZ, respectively. Comparatively higher Se levels were recorded in white polished rice varieties from the DZ and IZ than brown rice varieties from the same regions. Comparatively higher Se levels were observed in traditional rice varieties that varied from 77.51 to 163.8 μg/kg with the mean of 116.4 μg/kg. Among them, the highest Se content was reported in “Maa Vee”, which is widely recommended for diabetes, tuberculosis, constipation, hemorrhoids and cardiovascular diseases in traditional medicine. Based on the average daily consumption of rice by a person, the total daily intake (TDI) of Se was calculated. The TDI are 10.04 μg, 12.14 μg and 6.26 μg from rice of WZ, DZ and IZ, respectively. Results of the study also demonstrate that the Se concentration does not vary significantly among climatic zones. Though Se is available in other foods such as garlic and other vegetables, the recorded values for Se in rice are far below the recommended daily Se intake. Although some early studies indicated higher arsenic (As) contents in Sri Lankan rice, this study reveals that it is well below the Codex Alimentarius recommended maximum allowable limit.
Interaction of ferrous ions and free chlorine on microbiological quality of drinking water
(University of Peradeniya, Sri Lanka, 2015-11-06) Munasinghe, T.S.; Abayasekara, C.L.; Chandrajith, R.; Jayawardana, A.
University of Peradeniya has a nearly 60 year’s old water distribution network that consists mainly iron pipelines, most of which are now corroded to a large extent, adding iron rust to water. The aim of this study was therefore to investigate the possible consumption of free chlorine that added in to water for disinfection by iron dissolved from pipes. If free chlorine is reduced due to iron, the available amount of free chlorine would not be sufficient for the disinfection of microorganisms in water. A laboratory simulated study was carried out to investigate the possible reaction between ferrous ion and free chlorine in water using a series of and free chlorine mixtures. The effect of the reaction on the inhibition of microorganisms were also determined by spiking Serratia spp. (a total coliform) and Escherichia coli (a fecal coliform) into known mixtures of and free chlorine. The and free chlorine contents were measured spectrophotometerically while viable microbial count was assessed using membrane filtration technique that followed a confirmation tests. Furthermore free chlorine and microbiological quality were determined periodically using 27 water samples that were collected from various points of the University network. The results of this study indicated a rapid reaction between and free chlorine. The rate of free chlorine reduction was directly proportional to the amount of in water. Although inhibition of Serratia spp. and E. coli was observed due to free chlorine in water, the effect reduced drastically with increasing in water. Serratia sp. decreased gradually with the ascending chlorine levels at levels of 0.2 and 1.0 mg/L. Total inhibition of Serratia sp. were observed at 2 and 3 mg/L of while E. coli was inhibited at levels of 1.0, 2.0 and 3.0 mg/L. The content in the water distribution network of University of Peradeniya were ranged from <0.01 mg/L to 0.64 mg/L (desired value is <0.3 mg/L), while the desired free chlorine level (0.2 mg/L) was observed only at two locations (Faculty of Veterinary Science and Meewathura treatment plant). Total coliforms were detected in samples collected from Upper Hanthana, Marcus Fernando Hall, University Temple, Science Faculty, Mars Hall and Medical Faculty, while fecal coliforms were detected only in a sample from Marcus Fernando Hall. The results of microbiological test showed that water distributed from the Kandy Municipal Council and Meewathura plants are suitable for drinking, but water distributed from the Upper Hanthana plant was not suitable for human consumption according to the World Health Organization (WHO) Standards (0/CFU per 100 ml for both total and fecal coliforms) and Sri Lankan Standards (3/CFU per 100 ml for total coliforms and 0/CFU per 100 ml for fecal coliforms). The possible reason behind the unsuitable microbiological quality of water may be related to the reaction between and free chlorine in water. It was also noted that, a high level of in water was inhibitory to microorganisms in water and remove bacteria by formation of clumps.
Fluoride uptake by native and modified cattle bones from aqueous medium by batch adsorption
(University of Peradeniya, Sri Lanka, 2015-11-06) Gunathilake, B.A.P.T.; Iqbal, M.C.M.; Sumanasinghe, V.A.
Fluoride is found in excess compared to the WHO recommended levels in drinking water in the Kandy district. Health hazards such as dental fluorosis, skeletal fluorosis, crippling fluorosis and metabolic defects in lipids, proteins and vitamins are caused due to excess Fin drinking water. Among several defluoridation techniques, adsorption is the most effective and common method. The objective of this study was to investigate the effectiveness of the natural, economically feasible and eco-friendly materials such as plant leaves and cattle bones for removing fluoride ion from drinking water using batch adsorption method. Bio-adsorbent materials were collected and rinsed initially with tap water, and then with deionized water. Cleaned materials were air dried for 48 h and oven dried at for 48 h. Dried materials were sieved to obtain particle size between 250 – 350 μm. Batch adsorption experiments were conducted. A mass of 0.2 g of different adsorbents was added in 50 mL of 3 mg fluoride solution and shaken at 80 rpm in orbital shaker for 3 h. Thereafter, suspension was filtered and final Fconcentration was determined by fluoride ion-selective electrode. Chemical and physical modifications such as base treatment and bone char preparation were done to enhance the adsorption efficacy. Native bones were heated at 500oC for 3 h in muffle furnace to prepare bone char (BC). Effect of contact time and dosage were determined for chemical modification and effect of pH, kinetic studies, isotherm studies, desorption and adsorbent characterization for BC were carried out. adsorption on BC was maximum between pH 4-7 and equilibrium time for BC was 12 h. Pseudo second order kinetic model and Langmuir isotherm model described adsorption of on BC. The highest desorption was given with 0.1 M NaOH. BC enhances the efficacy of defluoridation from aqueous medium and is a cost effective and eco-friendly biosorbent.
Impacts of sea level rise and bed level accretion on residence time of Negombo lagoon, Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Pushpakumara, P.K.P.; Nandalal, K.D.W.; Weerakoon, S.B.
Water quality of an aquatic system is highly influenced by residence time (RT), which indicates how long a constituent is retained inside the system. This paper focuses on the effect of climate change induced future sea level rise (SLR) and associated bed level variations on RT of Negombo lagoon, Sri Lanka. The hydrodynamic behaviour of the lagoon was numerically simulated using Delft3D surface water modelling suite. The time required to drop the concentration of a constituent to of its original value was calculated as the RT of the lagoon. Anticipated maximum SLR of 79 cm at the end of the 21st century, predicted by the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, was considered as the future sea level of the lagoon. Three bed level accretion conditions, namely, no bed level accretion, accretion of the lagoon bed level by 50% of the SLR (partial bed level accretion condition) and accretion of the lagoon bed level similar to the SLR (full bed level accretion condition), in response to the anticipated SLR were considered. RT was calculated for each bed level variation under low (5.64 ) and high (41.93 ) streamflow conditions. Model predicted RTs of the lagoon at present are 22.4 days and 12.4 days under low and high streamflow conditions, respectively. Under the absence of bed level accretion, RT is increased up to 32.2 days (+43.7%) and 17.8 days (+43.5%) due to SLR in low and high streamflow periods, respectively. Under partial bed level accretion, RT is decreased up to 18.1 days (-19.2%) and 12 days (-3.2%) in low and high streamflow periods, respectively. RT is decreased up to 13.4 days (-40.2%) and 8.5 days (-31.5%), under full bed level accretion, in low and high streamflow periods, respectively. The results reveal that the climate change induced future SLR and the associated bed level accretion influence the RT of the lagoon altering the lagoon water quality.
P-T-t Evolution of calc-silicate rocks in the South-Western highland complex of Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Sameera, K.A.G.; Perera, L.R.K.
Recent studies on calc-silicate rocks from the Southwestern Highland Complex of Sri Lanka have renewed the interest on the reconstruction of the P-T-t and fluid evolution in this part of the island. Present study is another contribution to understand the P-T-t path and fluid conditions of the calc-silicate lithologies around Galle and Middeniya-Embilipitiya areas in the Southwest. Based on petrography and mineral assemblages, the studied calc-silicate lithologies can be subdivided into three main groups; Group I – wollastonite-bearing but grossularite-absent assemblages, Group II – grossularite-bearing but wollastonite-absent assemblages, Group III - both wollastonite and grossularite-absent assemblages. Formation of different assemblages is possibly a result of peak metamorphic P, T conditions, the chemistry of protoliths, graphite precipitation and response to fluctuation of level during prograde path. Critical reaction textures in Group I lithologies indicate breakdown of, (1) wollastonite calcite + quartz, (2) wollastonite + dolomite → calcite + diopside, (3) scapolite → calcite + quartz + plagioclase, (4) alkali feldspar + wollastonite → scapolite + quartz + K+, that are important in re-constructing the P-T-t evolution of the terrain. Diopside rims around quartz in Group II assemblage suggest the reaction, (5) dolomite + quartz → diopside + CO2. In addition, local occurrences of fluids involving reaction textures such as myrmekitic intergrowth of plagioclase + quartz between calcite + K-feldspar and replacement of diopside by hornblende have been observed in calc-silicate rocks from the study area. Peak metamorphic assemblage of the Group I suggests a stabilization temperature of about 800-8500C at 5 kbar, and 0.2 in the fluid phase. The retrograde reactions (1), (2) and (3) suggest isobaric cooling (IBC) following peak metamorphism during which internal fluid buffering prevailed. But the IBC reaction anorthite + wollastonite → grossularite + quartz, noted from elsewhere was not present in the studied samples perhaps due to lower lithostatic pressure in the study area. The reactions (4) and (5) suggest isothermal decompression (ITD) following the IBC path, and other fluid involving reactions noted in the study area suggest both hydration and influx during final stages of metamorphic evolution. The retrograde reaction textures in the studied calc-silicates and the inferred IBC and ITD P-T-t segments for the Southwestern Highland Complex correlate well with the results of previous P-T-t studies of calc-silicate, pelitic and mafic rocks in the Highland Complex. Further, presence of grossularite-absent assemblages, the reaction textures (1), (3) and (4), and the inferred P-T-t path for the study area strongly correlate well with mineral assemblages, reaction textures and P-T- t evolution in the Kerala Khondalite Belt within the Trivandrum Block of Southern India.
Spatial variability of soil properties in a calcic red latosol soil scape in the nothern area of Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Nerogini, S.; Vitharana, U.W.A.; Karunainathan, T.
The information on the spatial variability of soil properties is vital for the better management of soil and to increase the crop productivity. This study was conducted to explore the short-scale spatial variability of selected chemical and physical soil properties of a Calcic Red Latosol soil scape in the Alaveddi area in the Jaffna district. The study area consisted of 2.5 ha and samples were collected within the plough depth (0- 30 cm) by using stratified random sampling scheme. This was achieved by firstly defining a sampling (spacing 29 x 29 m) grid. Subsequently, a random sample was added within each grid cell. The variability of soil clay content, silt content, sand content, organic matter (OM), pH (soil to water ratio of 1:2.5) , electrical conductivity (EC) (soil to water ratio of 1:5) were investigated for all the samples (n=40) and available phosphorous, exchangeable potassium were investigated for selected samples (n=9) by means of classical and geo statistical analysis techniques. The coefficient of variation of properties ranged from 4% (pH) to 32% (clay content). The experimental variograms calculated for soil properties were best fitted with spherical model. According to the relative nugget effect (RNE -ratio of nugget to the sill) of variograms, the clay content, sand content, silt content, electrical conductivity and organic matter exhibited a highly spatially structured variability (RNE < 25 %), whereas a medium structured variability was observed for soil pH (RNE 25-75 %). The observed spatial dependencies of soil properties indicated that sampling space for future studies can be ranged from 20 m (pH) to 70 m (sand). The maps of texture, OM further illustrated a strong short-scale spatial variability indicating the potential of site-specific soil management in the study area.
Relationship between biology students’ G.C.E. (A/L) results and their mathematics results at G.C.E. (O/L): a case study in Bandarawela educational zone
(University of Peradeniya, 2016-10-05) Hettiarachchi, B.H.A.C.K.; Chandrasena, W.D.; Jayasundera, A.C.A.
The G.C.E. (O/L) and the G.C.E. (A/L) Examinations are the milestones in secondary education which determine the golden key to admirable future to Sri Lankan students. According to the available statistics the achievement level of students at the G.C.E. (A/L) is still less than the expected level despite the annual allocation of human and physical resources by the Sri Lankan government with the aim of improving students’ performance. This could be due to several interrelated factors such as lack of interest, poor academic abilities, poor teaching methods, weak teacher characteristics and other related issues. This study focuses on finding the relationship between biology students’ G.C.E. (A/L) results and their mathematics results at G.C.E. (O/L).This is a mixed method study. Questionnaires, documents, and semi- structured interview schedules were used in the data collection process. The sample included of167 G.C.E. (A/L) Biology students from Bandarawela Educational Zone. Data analysis was performed through basic statistical procedures and qualitative data analytic techniques. Results show that the high percentage of students who pass their G.C.E. (A/L) examination at their first attempt had “A” Grade for their G.C.E. (O/L) Mathematics compared to the students who had low results for their G.C.E. (A/L).Moreover, high percentage of students who obtained more than “S” Grade for G.C.E. (A/L) Physics were the students who had “A” Grade for their G.C.E. (O\L) Mathematics. The high percentage of students who passed their G.C.E. (A/L) examination at their first attempt was the students who have sat for their both G.C.E. (O/L) and G.C.E. (A/L) examination at the same school. Thus, G.C.E. (O/L) Mathematics results directly affect for G.C.E (A/L) Biology students’ performance at the examination. Interview data reveals that the students’ G.C.E. (A/L) Biology stream results are better when they have enthusiasm in all sections in G.C.E. (O/L) Mathematics. Further, the change of the school after their G.C.E. (O/L) could also affect students’ performance at G.C.E. (A/L) in the bio-science stream. Hence, these findings could be considered in remedying the prevailing situation through suitable practices to enhance the status of science education in Sri Lanka.
Antioxidant properties of selected traditional rice varieties in Sri Lanka
(University of Peradeniya, 2016-11) Kariyawasam, T.I.; Godakumbura, P.I.; Prashantha, M.A.B.; Premakumara, G.A.S.; Abeysekera, W.K.S.M.
Rice is the major cereal crop as well as the main staple food in Sri Lanka and other regions of Asia. Previous studies on some of the traditional rice varieties of Sri Lanka (STRV) show higher nutritional value and bioactivity when compared with improved rice varieties cultivated in Sri Lanka. This study evaluates the antioxidant properties of extracts of selected STRV. Methanolic extracts of four STRV (Kalu Heenati, Pokkali, Kahawanu and Sudu Murunga) were used for in vitro antioxidant assays. Antioxidant properties of STRV were measured using total polyphenolic content (TPC), 1, 1- diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging, and 2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging assays. Methanolic extracts of selected rice varieties showed potent antioxidant activity. Mean TPC of STRV were in the range of 1.66 ± 0.08 – 7.66 ± 0.17 mg gallic acid equivalents/g. Mean DPPH and ABTS antioxidant properties were in the ranges of 0.56 ± 0.03 – 2.58 ± 0.15 and 3.83 ± 1.08 – 13.14 ± 0.90 mmol Trolox equivalents/ 100g flour, respectively. The order of mean TPC in the rice varieties was Pokkali > Kalu Heenati > Kahawanu > Sudu Murunga. Results show a difference among rice varieties in scavenging activity for DPPH and ABTS radicals. The order of scavenging activity for DPPH radicals was Kalu Heenati > Pokkali > Kahawanu > Sudu Murunga while for ABTS radicals, the order was Pokkali > Kalu Heenati > Kahawanu > Sudu Murunga. Accordingly the antioxidant power of the extracts was in the order of Pokkali > Kalu Heenati > Kahawanu > Sudu Murunga. Rice varieties having red pericarps displayed higher antioxidant activities when compared to rice varieties having white pericarps. The present study highlights the importance of STRV as potential sources of antioxidant compounds, especially the varieties of Pokkali and Kalu Heenati. These traditional rice varieties may be able to limit the risk of various chronic diseases associated with oxidative stress and this data will be useful to nutritionists for formulating therapeutic diets rich in antioxidants.
Identification of mutations in BRCA1 exon 11 of breast cancer confirmed patients and in at risk individuals
(University of Peradeniya, 2016-11) Jayasooriya, K.M.D.; Hewawithana, P.B.; Galketiya, K.B.; Wickramasinghe, S.; Yatawara, L.
Breast cancer is the commonest malignancy among females. Of the risk factors leading to develop breast cancer, germline mutations and sequence variance of breast cancer susceptibility genes play a major role.This study was conducted to identify germline mutations in exon 11 of BRCA1 breast cancer susceptibility gene.Exon 11of BRCA1is a common region of mutations in breast cancer patients and also in individuals with a family history of breast cancer. The study consists of a total of 43 breast cancer patients with family history (N=12) and without a family history (N=31). About 26 currently unaffected individuals with first or second degree relatives having breast cancer and 25 controls (those who are without any personnel or family history of any cancer) were also included. Self-administered questionnaires were given to the participants to evaluate the personal and family histories of breast and other cancers. Blood samples were collected for detection of mutations in exon 11 of BRCA1 gene. Following genomic DNA extraction, mutation detection was performed using polymerase chain reaction by amplifying exon 11which consist of 3426 base pairs that represents 60% of the coding sequence. Upon amplification, PCR products which showed abnormal migration patterns in gel electrophoresis were sequenced. Mean age of the onset for 43 women diagnosed with breast cancer in this study was 52.256±9.70 years. Mean age at diagnosis of breast cancer patients with family history was 55.08 ± 6.788 and without family history was 51.16 ±10.51. Furthermore, abnormal migration patterns in PCR products were observed in breast cancer confirmed patients and in at risk individuals upon gel electrophoresis. PCR products which show the size variations were subjected for direct sequencing. Seventeen sequence variations were found in the exon 11 of three sequenced samples. G3135delC/exon 11 was observed. Previously reported six polymorphisms were also identified in these sequences. Results obtained from this study confirmed the presence of single nucleotide polymorphisms in the exon 11 of BRCA1 gene of the individuals included in this study.
In vitro anti Candida effect of Sri Lankan virgin coconut oil
(University of Peradeniya, 2016-11) Garusinghe, N.; Jayatilake, J.A.M.S.; Madujith,T.
Coconut oil obtained from Cocus nucifera is commonly used in Sri Lankan food. It is also a skin and hair remedy in native medicine. Candida is a commensal fungus found in human mucosa and skin. Whereas, Sri Lanka is a leading coconut producer in the world Sri Lankan virgin coconut oil (VCO) has not been explored for anti-Candida effect. This study aimed to investigate anti Candida effect of Sri Lankan VCO. VCO extracted by fermentation method was used for the study. Mature coconut kernel was scraped and allowed for fermentation under sterile conditions. Resultant oil was separated by heating at a controlled temperature. Thus extracted VCO was divided into two samples. One sample was used directly to check the anti-Candida effect while other sample was subjected to partial hydrolysis. Hydrolysis was done by reflux condensing on sand bath using methanolic sodium hydroxide. Hydrolyzed oil was neutralized and extracted in hexane. Anti-Candida effect for both unhydrolyzed and hydrolyzed samples were tested against five species of Candida; Candida albicans (ATCC90028), Candida glabrata (ATCC90030), Candida krusei (ATCC6258), Candida parapsilosis (ATCC22019), Candida tropicalis (ATCC13803). Several diffusion techniques on Sabouraud’s agar including disk diffusion, well diffusion and direct drop method were used to demonstrate anti Candida effect. Unhydrolyzed VCO did not produce any significant inhibition zones against any of the Candida species tested. In contrast, hydrolyzed VCO produced significant inhibition zones against all Candida species tested. C. glabrata showed the highest mean inhibition zone (40.88mm) followed by C. Tropicalis (36.00mm), C. Parapsilosis (32.11mm) C.albicans (28.22mm) and C. krusei (23.88mm). This study demonstrates that partially hydrolyzed Sri Lankan VCO obtained from fermentation method have anti-Candida effects which could be used as an alternative to resistant Candida in the future. Use of hydrolyzed Sri Lankan VCO in skin remedies may help control Candida colonization.
Setting up a weather research and forecasting model for rainfall prediction in Upper Mahaweli basin
(University of Peradeniya, 2016-11-05) Herath, H.M.V.V.; Dayananda, R.G.A.B.; Weerakoon, S.B.
Upper Mahaweli basin, which is the Mahaweli River sub-basin above the Polgolla reservoir, has a special importance in the water management of Sri Lanka.Reliable weather prediction in the basin is especially important for the operation of a number of reservoirs in the basin. Simulating the natural atmosphere by using computer models is the main tool that is used for weather prediction. In this study, Weather Research and Forecasting (WRF) model is used to downscale global scale weather prediction data to obtain rainfall prediction over the Upper Mahaweli basin. WRF model is a regional weather forecasting model and it is a mesoscale numerical weather prediction system designed to serve both operational forecasting and atmospheric research needs. The WRF model was calibrated using National Centers for Environmental Prediction (NCEP) reanalysis data for forecasting extreme rainfall in the Upper Mahaweli basin by selecting appropriate physics options of the model including microphysics schemes, cumulus parameterization schemes, land surface schemes, planetary boundary layer schemes, surface layer schemes and radiation physics schemes. WRF predictions were compared with the observed point rainfall data of selected gauging stations within the catchment. Observed point rainfall data were distributed to the same grid of WRF predictions by GIS based Inverse Distance Weighting (IDW) technique. After the comparison of WRF prediction with observed rainfall, a most appropriate physics combination was selected for rainfall prediction. Then the calibrated model was satisfactorily validated for few other rainfall events in the reservoir catchment. NSSL 2-mom microphysics scheme, Kain-Fritsch cumulus parameterization scheme, CAM shortwave radiation scheme, RRTM long wave radiation scheme, YSU planetary boundary layer scheme, Noah land surface scheme and Revised MM5 surface layer scheme with other default physics options are the most suitable physics combinations for the Upper Mahaweli basin. This combination gave the least Root Mean Square Error (RMSE) of 11 mm at the calibration stage. In the validation process the model was run with optimized physics combination and RMSEs of 18 mm and 20 mm were obtained for two other extreme rainfall events. Calibrated WRF model is a useful tool for rainfall prediction in Upper Mahaweli basin.
Impact of elevation and weed management methods on variability of Soil Organic Carbon stocks in an Ultisol
(University of Peradeniya, 2016-11-05) Jayasekara, M.J.P.T.M.; Vitharana, U.W.A.; Peiris, H.M.P.
Soil organic carbon (SOC) stocks play a significant role in regulating global warming.Generation of detailed maps of SOC stocks is necessary to assess its contribution for C sequestration at regional scale. Identifying environmental controllers of SOC stocks is a requirement for designing sampling schemes and detailed mapping of SOC stocks. This study was conducted in Hapugasthanna Tea Estate in Maskeliya(WU1) to quantify the spatial variability of SOC stocks while investigating impact of elevation, soil properties and weed management on SOC stocksin a slopyUltisol soil-scape. Topsoil (0-30 cm) samples were collected from 44 locations using grid combined random sampling scheme.Three fields where herbicides applied in three months interval and three fields where herbicide free integrated weed management (HFIWM) practiced for three yearswere selected and samples were taken within each field. These samples were analyzed for SOC, bulk density, soil texture, saturated hydraulic conductivity, pH and EC.Organic carbon content and bulk density were used to calculate SOC stocks. Shuttle Radar Topography Mission (SRTM) 90m Digital Elevation Model was used to extract the elevation data. Average SOC stock within the study area was 64.8 t ha-1and coefficient of variation (CV=18.4%) indicated medium variability. Other soil properties(pH, EC, hydraulic conductivity)showed CVs from 9 % to 35 % indicating medium variability. Soil organic carbon stocks showed a positive correlation (r = 0.4) with bulk density and clay content. A negative correlation (r = -0.31) was observed between SOC stocks and elevation. Agreeing with this finding, interpolated map showed higher SOC stocks in low elevation compared to higher elevation. Variogram of SOC indicated moderately structured spatial variability. Average SOC stock in HFIWM fields (80.2 t ha-1) was larger than herbicide applied fields (65.6 t ha-1) (P = 0.07). We found a medium level spatial variability of SOC stocks in slopy Ultisol soil- scape. Topography is one of the main controllers of spatial variability of SOC stocks. Thus, elevation and topographic attributes can be used as co-variates for sampling and subsequent mapping of SOC stocks. Weedicide free weed management enhances soil carbon sequestration in tea growing Ultisols.
Consumer acceptance of mobile value added services: a model based on literature
(University of Peradeniya, 2016-11-05) Bandara, A.M.A.S.M.; Wickramasuriya, H.V.A.
The number of mobile connections exceeded the population of Sri Lanka by the year 2014 indicating that the potential customer base is diminishing. In line with the global trend, offering different Value Added Services (VAS) to the existing customer base was identified as a potential means of growth by the mobile service providers (MSPs) where the knowhow of the influential factors on the consumer adoption of mobile VAS would be important since the earnings from VAS were reported to be not substantial due to the lower adoption levels by the consumers. On the other hand, many researches were conducted on the determinants of technology adoption and usage making it a prominent research area throughout the last few decades. However, a research gap can still be identified in relation to the adoption of technologies in the consumer context as the earlier researchers have given a prominence to the technologies in the organizational context. From an extensive literature search using Google Scholar®, a total of 20 relevant articles published later than 2010 were identified and the factors that have been investigated in the selected studies were classified according to their similarity and patterns of their findings. Among the identified models, the Extended Unified Theory of Acceptance and Use of Technology (UTAUT2) was selected as the theoretical base since it was specifically design for the technologies available in the consumer context. Moreover, UTAUT is an extension to the Unified Theory of Acceptance and Use of Technology which is a review and consolidation of the constructs of eight models that were used in explaining the information systems usage and behaviour. The developed model consists of two constructs in addition to the constructs of UTAUT2 i.e. the Perceived English Language Proficiency (EL) and the Type of the Connection (TC). Having EL in the model is important as the MSPs use English as the primary language of nonverbal communication. Such dependency may act as a barrier to the technology use. TC on the other hand, indicates the major categories of mobile connections based on the billing method (i.e. pre-paid and post-paid) which may have an impact on the adoption and use of VAS. In line with the UTAUT2, Use Behaviour (UB) has been identified as the dependent variable of the proposed model. UB was conceptualized to have direct relationships with Behavioural Intention (BI), Facilitation Conditions (FC), Habit (HB), and Experience on Mobile Technologies (EX), EL, TC and Demographic Factors (DF). On the other hand, BI was conceptualized to have direct relationships with all independent constructs (i.e. Performance Expectancy (PE), Effort Expectancy (EE), Social Influence (SI), Price Value (PV), Hedonic Motivation (HM), FC, HB, EX, EL, TC and DF) making it an intermediary variable. However, the proposed model requires empirical validation before practical usage.
Body composition of secondary school children in Sri Lanka: a study to develop a set of morphological fitness reference values
(University of Peradeniya, 2016-11-05) Senevirathne, K.S.H.M.V.W.W; Wijesundera, S.D.K.
The overweight and obesity prevalence among children in Sri Lanka show different ranges according to provincial and gender variations. In recent years, the interest in physical fitness assessment in school children has increased in other countries, but in Sri Lanka it is still very low. There is a dearth of reference values of physical fitness including body mass index (BMI) for secondary school children in Sri Lanka. The objectives of this study were to contribute to the available knowledge concerning the assessment of body composition (Body Mass Index), identifying sex and age-related norms of body mass index of the secondary school children in Sri Lanka and to compare BMI values of Sri Lankan children with the relevant values of children in other countries. A quantitative approach was used in this study. Physical fitness assessments were implemented to measure BMI of 1229 students (638 boys and 591 girls, aged between 11 years and 17 years), which was a randomly selected sample in the Kandy District. All the data were computed and analyzed to formulate test norms as percentile values, stratified by chronological age groups separately for boys and girls. All the calculations were performed using SPSS vs. 17 for windows. The significant observation is that the BMI percentiles of P5, P10, P90 and P95 of the boys in the age groups 11, 12 and 13 are greater than those of the boys in the age group of 14 years. Reasons may be due to changes occurred in adolescent period. Except this unusual pattern, it is revealed that BMI percentiles of the boys and girls gradually increase according to the age over a period from 11 years of age to 17 years. According to the data the lowest P5 of boys’ BMI is approximately 13 and the highest P5 is 17 .4. Furthermore, the lowest P95 of boys BMI is approximately 18 and the highest P95 is approximately 22 .6. Furthermore, the lowest P5 of girls BMI is approximately 14 and the highest P5 is approximately 17. Furthermore, the lowest P95 of girls BMI was found for the year 18 range and the highest P95 was found in 22 .9 range. It can be observed that although the BMI levels of Sri Lankan children (both boys and girls) are not in the range of ‘Needs Improvement-Health Risk (NI-HR)’ but in the range of ‘Needs improvement’. They are in the margin of very lean level according to the USA norms. However, we cannot say BMI level of Sri Lankan boys and girls are not in a satisfactory level compared to USA standards. It should also be noted that since these figures are normative base values, such norms are identical only for a specific population.
Outcomes of the implementation of a task based approach in the EAP (English for Academic Purposes) classroom
(University of Peradeniya, 2016-11-05) Izzadeen, F.S.
The task based approach has gained recognition as an important element in the language classroom as a method to move learners from reproductive language use to creative language use, resulting in maximum engagement in language acquisition through requiring them to draw upon their emerging language skills and resources in an integrated manner (Nunan, 2004). The objective of this study was to explore the effects of tasks in pedagogy in the English as a second language classroom for undergraduates. This was achieved through investigating dialogic exchanges, involving noticing, formulation and hypothesis testing, produced as a result of stimulus from a pedagogical task. A task was designed for second year undergraduates at the Faculty of Science, who are learners of English as a Second Language (ESL) following the English for Academic Purposes course. The task which was designed to reinforce structural and grammatical skills while focusing on the meaning conveyed and involved learners using and manipulating previously taught forms to fulfill the functions of the task. The task was structured to engender discussion and foster peer learning. Learners were provided with incomplete information in the form of three short excerpts from a newspaper article. Working in groups the learners had to decide on the storyline of the article guided by the given excerpts. As the final outcome, each group had to write an article for a newspaper about the incident incorporating the given data and adding further details. The structures targeted in this task included the past tense, reported speech, lexical items and sequence markers, all of which the students had encountered in previous lessons. The learning outcome was measured through Language Related Episodes (LRE) that occurred in the process of carrying out the task. Success in the task was measured in terms of accuracy of linguistic use and the achievement of the task. Investigation of the LREs produced during the task showed that this task resulted in peer learning and achieved the aim of pushing learners to think about, manipulate and practice the target language features. Thus, in conclusion, well planned tasks can engender language learning in a second language context by pushing learners to notice, interact and formulate language, focusing on both form and meaning.
Impact of intervention on socio-economic status of village chicken rearing farmers: a case in Karuwalagaswewa and Thirappane veterinary divisions
(University of Peradeniya, 2016-11-05) Thilini, H.W.L.; Korale Gedara, P.; Silva, G.L.L.P.
Village chickens contribute to 15% of the national egg production. Although the village chickens arepoor producers of eggs, farmers tend to rear them because of the favorable characteristics exhibited by village chicken. This study was conducted to evaluate the change in the socio economic status of village chicken farmers in Karuwalagaswewa and Thirappane veterinary ranges due to intervention done by a recent project. A sample of eighty seven farmers representing four villages was interviewed by a detailed survey. The improvement of the village chicken farmers in terms of livelihood and farming conditions after the intervention was determined using Wilcoxon sign rank test and simple mean percentages. A cost-benefit analysis was conducted using Net Present Value and Benefit Cost Ratio to evaluate the worthiness of establishing mini hatcheries in both sites. The results of the cost-benefit analysis showed that the establishment of mini hatcheries was a worthy intervention. The awareness about diseases, poultry housing management, knowledge level of farmers on poultry farming, connection with other farmers, communication ability and knowledge on marketing were significantly high (P<0.05) among the farmers who participated in the project as a result of the training programs conducted by the project. However, obtaining veterinary services and the practice of using vaccinations to prevent diseases has not significantly improved (P>0.05) by the interventions done through the project. Nevertheless, the ranking index indicated that the most affecting constraint revealed by village chicken farmers was lapses in obtaining veterinary services. Thus, the findings of the present study indicated that the project interventions could make an impact on direct drivers of socio-economic development of the farming community whereas indirect drivers such as linking with service providers and allied offices was least influenced. Accordingly, the overall impact of the project intervention on socio economic development of village chicken farmers was high. However, the impact could be further enhanced through an integrated approach in addressing indirect drivers influencing socio-economic status of farmers.

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