PURSE 2013

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The education component of human capital: explorations with an indicator for Sri Lanka
(University of Peradeniya, Sri Lanka, 2019-10-17) Abayasekara, C. R.; Madadeniya, M. G. C. N.
Introduction Education is a primary component of ‘human capital’, a key factor of production (Becker 1992, 1964; Romer, 1986; Lucas, 1988). Physical indicators of education are either ‘input-based’, as in years of schooling and enrollment ratios, or ‘outcome-based’ as in literacy rate and ‘Learning- Adjusted Years of Schooling’ (World Bank, 2019). A recent approach (Sumaiya and Abayasekara, 2016; Kariyapperuma, 2018) measures the human capital of the employed population for Sri Lanka through an ‘Education-adjusted Employment Index’ (EAEI), to account for the changing composition of education over time. The computed index does not cover the unemployed and those outside the labor force; nor does it differentiate between genders. It has also not been ‘validated’ as an alternative indicator to others in use. The research problem therefore constitutes the following questions: How does the index and its rate of change compare among males and females, employed and unemployed, and those within and outside the labor force in Sri Lanka; and does public expenditure on human capital have an impact on education-based human capital accumulation as measured by the index?.
The usefulness of pre employment chest radiography as a health screening method prior to employment
(The University of Peradeniya, 2013-07-04) Hewavithana, P. B.; Perera, M. G. R. S.
Employers often use tests and other selection procedures to screen applicants prior to employment. The goal of the pre-employment examination is to determine whether an individual is fit to perform his or her job without risk to himself or others. For more than two decades chest radiographs have been performed as a pre employment health assessment among all the permanent staff members in University of Peradeniya. Although researchers in other countries have recently questioned the value of this long standing practice, no attempt has been made to consider this evidence in relation to Sri Lanka. The objective of this study was to determine the usefulness of pre employment chest radiography among the employees of the University of Peradeniya as a health screening method prior to employment, by detecting pulmonary tuberculosis. This was a retrospective study on 702 records of chest radiographs, performed at the Health Centre University of Peradeniya, as a routine medical screening prior to employment, from1st January 1991 to 31st December 2011. Of the 702 chest radiographic reports 685 (97.58%) were normal and 17 (2.42%) were considered as having abnormalities. Among those 17 chest radiography reports, there were 2 with mild cardiomegaly (0.29%), 5 hyper inflated lungs or mild basal emphysema (0.71%), one hilar enlargement (0.14%), one healed rib fracture (0.14%) and 7 thoracic scoliosis (0.10%). There were no positive results with respect to active pulmonary TB. Only one report (0.14%) revealed healed pulmonary tuberculosis. In conclusion, the majority of the study sample had normal chest radiographs whereas only 2 % had abnormal examinations. Chest radiograph could be considered a useful screening tool to exclude chest abnormalities. However it may not be useful as a screening method to exclude pulmonary tuberculosis.
Subspace separation for performance improvement in fetal cardiac signal extraction
(The University of Peradeniya, 2013-07-04) Soysa, W. N. M.; Wijayakulasooriya, J. V.; Godaliyadda, G. M. R. I.; Ekanayake, M. P. B.; Kandauda, I. C.
To overcome risks during pregnancy, it is important to generate fetal heart signals with minimal noise/distortion, and with as much information as possible. However, interference of various types of unwanted noisy signals such as maternal heart signal and receiver noise cause difficulty in the interpretation of the fetal heart conditions through the extracted fetal cardiac signal. The maternal heart signal interference can be removed using an adaptive Wiener filter. Cardiac signals captured from maternal abdomen and the chest are used as the reference and the input signals into the Weiner filter, respectively. The Wiener filter attempts to model the path between maternal chest and abdomen, thereby effectively cancelling the maternal cardiac signal from the abdomen sensor measurement. This concept is called the principle of correlation cancellation in the Wiener filter. However, the Wiener filter is incapable of removing uncorrelated signals that are present in the input and the reference signals of the Wiener filter itself. Therefore, noise in the reference signal leaks directly to the extracted signal corrupting it. Further, noise at the filter causes a mismatch in the Wiener filter model. Due to this model mismatch, a mismatch noise is added to the extracted signal further corrupting it. Therefore, it is important to minimize the noise in the Wiener filter input and reference signal. To minimize the sensory noise, normally, standard low pass IIR and FIR filtering techniques are utilized. This eliminates high frequency noise to a reasonable degree. But such techniques are susceptible to high noise environments, which in addition tend to be non- stationary. Therefore, we have proposed an Eigen filter based subspace separation technique. The subspace filters utilized have the capability to realize complicated filter structures, thereby improving performance under noisy conditions when all other methods fail. To verify the performance enhancement of the proposed techniques, we have measured the extracted signals correlation to an ideal benchmark signal under varying noise levels. It was discovered that while the performance of other techniques decayed exponentially, only a slight linear performance degradation occurred in the subspace filters, as noise is increased. This clearly indicates the versatility of the subspace technique under high noise levels. Thereafter, we generated a spectral estimate of the extracted signal for different filter types and used appropriate parameters to generate cluster diagrams. The results further verified how the subspace filter based method best replicated the ideal fetal cardiac signal which is desired.
Surfactant-assisted synthesis of nanosized precipitated calcium carbonate and magnesium hydroxide from marble
(The University of Peradeniya, 2013-07-04) Mantilaka, M. M. M. G. P.; Wijesinghe, W. P. S. L.; Rajapakse, R. M. G.; Karunaratne, D. G. G. P.; Pitawala, H. M. T. G. A.
Precipitated Calcium Carbonate (PCC) and magnesium hydroxide (Mg(OH)₂) are products in high demand, and are widely used in Sri Lanka. Therefore, the country spends large sums of money for these products despite there being a high possibility to synthesize them using extensively distributed marbles. However, the production of PCC and Mg(OH)₂ has not yet been achieved. This study describes a novel technique to synthesize nanoparticles of PCC and Mg(OH)₂ simultaneously from Sri Lankan marbles. This is a timely requirement to enhance the utility of Sri Lankan marbles and to reduce the cost of importing these products. Marble samples collected from selected locations were crushed, ground and <100 μm fraction was heated at 1000 °C for 4 h to produce calcined dolomite (CaO.MgO). 5 g of calcined dolomite was dissolved in 100 mL of 0.5 M sucrose solution and stirred for an hour. The solution was filtered under suction to separate the precipitated MgO with impurities from soluble calcium sucrate. 0.5 mL of triton X 100 was mixed with calcium sucrate and then 100 mL of 0.5 M Na₂CO ₃ solution was added dropwise to the mixture to synthesize PCC nanoparticles. The function of triton X 100, a nonionic surfactant was to keep resulting products in nanoscale by preventing particle aggregation. The separated MgO component was dissolved in 1.0 HCl solution and filtered to obtain 25.0 mL of 1.0 M MgCl₂ solution with pH of 6.0. Triton X 100 (0.5 mL) was mixed with 50 mL of 1.0 M NaOH. 25 mL of MgCl₂ solution was added dropwise to the reaction mixture while stirring to synthesize Mg(OH)₂ nanoparticles. The final powders of PCC and Mg(OH)₂ products were dried. X-ray Diffraction (XRD) analysis confirmed the presence of calcite in PCC and brucite in Mg(OH)₂. The estimated average particle sizes of PCC and Mg(OH)₂ products by means of Debye–Scherrer formula were 45.1 nm and 11.8 nm respectively. The products were further characterized by using Fourier transform infrared spectroscopy (FTIR) and Thermo Gravimetric Analysis (TGA). Weight percentage of Ca in the Mg(OH)₂ product was 1.1% and weight percentage of Mg in PCC was 0.6%. These results confirm that both PCC and Mg(OH)₂ nanoparticles can be synthesized using Sri Lankan dolomitic marbles with sufficient quality to meet with commercial requirements.
Subcutis form of transmissible venereal tumour in a dog: a case report
(The University of Peradeniya, 2013-07-04) Karunaratna, A. M. D. S.; Bandara, A. M. R.; Rathnayaka, R. M. D. S.; Lokumarambe, c.; Ariyarathna, H. M. H. S.; Wijayawardhane, K. A. N.
Transmissible venereal tumour (TVT) is a common round cell tumour among sexually active dogs. TVT is usually transmitted through copulation, whereas direct transplantation of tumour cells onto abraded or intact mucosae of nasal and oral cavities, eyes and skin can occur either by licking or sniffing of the affected genitalia. The most common clinical signs of TVT are presence of pinkish red, friable, cauliflower-like masses on the mucosae of external genitalia. Masses may also be rarely found in other areas, such as oral mucosae, lips, peritoneum, tonsils, eyes, liver, kidneys, spleen, lungs, musculature and subcutis. The objective of this communication is to enhance the awareness of small animal veterinary practitioners in the diagnosis, treatment and management of the subcutis form of TVT. A four-year-old, intact male boxer dog was presented to the Veterinary Teaching Hospital with the complaint of multiple nodules all over the body, which had been rapidly growing over a two week period. Clinical examination revealed firm and freely movable dermal and subcutaneous nodules, ranging from 0.5-4.0 cm in diameter. Cytology of smears from fine needle aspirations and histopathology of biopsies from nodules revealed the subcutis form of TVT. Thoracic radiographs did not show signs of metastasis. Treatment was initiated to control the tumour and minimise adverse effects of chemotherapy. Therefore, weekly administration of vincristine sulphate (0.025 mg/m², IV) was selected as the chemotherapeutic agent. Amoxicillin-clavulanic acid (20 mg/kg, IV, b.i.d) was administered prophylactically, followed by oral medication of the same to prevent secondary infections which may occur due to chemotherapy-induced immunosuppression. Hepatic supportives, haematinics and anti-ulcer drugs were given to minimise adverse effects of chemotherapy. The animal was closely monitored following treatment. Marked reduction in the size (0.3-2.5 cm) of the dermal and subcutaneous masses was observed five days after initial treatment. A second dose of vincristine sulphate given one week later resulted in complete remission of the tumours. In conclusion, TVT should be considered as a differential diagnosis in cases presented with subcutaneous and dermal nodules.
Modelling of acoustic signals based on optimum pole structure for material based classification
(The University of Peradeniya, 2013-07-04) Nettasinghe, D. B. W.; Pollwaththage, N. N.; Ratnayake, T. A.; Wijayakulasooriya, J. V.; Godaliyadda, G. M. R. I.; Ekanayake, M. P. B.
In this paper, we utilize an autoregressive (AR) model for acoustic signal modeling and classification. It is shown in this work that through proper estimation of the pole structure classification, performance can be improved for material based classification. Classification based on the acoustic properties of materials and systems, is used in many applications in various fields. For example, sports – Snickometer system in cricket, medical diagnosis - acoustic stethoscopes, automobile fault diagnosis - engine trouble, speech processing - automatic speech recognition. The modelling and classification of these data is performed here using three types of signals generated by the impacts between glass–metal (GM), glass–plastic (GP) and metal– plastic (MP) with a database consisting of forty six signals from each class. These three types of signals were modelled using an AR model structure given by: Though the frequency spectrum can be obtained by directly substituting z=eʲʷ, inaccurate pole locations can result due to resolution limitation. In order to circumvent this resolution issue, we resort to “residue method” which can be described as, where, Aᵢ is the residue corresponding to each pole Pᵢ. In particular, we may interpret that Aᵢ represents the “strength” or the level of contribution of pole Pᵢ. The resultant spectrums were then utilized with the AR model for twenty five coefficients in order to extract parameters for classification. The optimum number of poles were obtained using pole-zero plots, hence two coefficients were selected for the classification. As another method of minimizing the error, the optimum number of poles was selected to be four, since it yielded the minimum squared error. According to this analysis, it was observed that there is a clear separation of the three signals into different cluster regions with a minimal number of false alarms. In conclusion, we show that, signals can be classified according to their acoustic system using AR modelling with the optimum number of poles, as less number of poles will not model the signal accurately and large number of poles will model the noise components as well, which will lead to erroneous results.
Right view (samma ditti) as an ethical and cognitive basis for self transformation: a critical study
(The University of Peradeniya, 2013-07-04) Pemananda, Ven. Unapana
The Right View in Theravada Buddhist teachings is generally explained as the knowledge of the Four Noble Truths: Suffering, the Cause of Suffering, the Cessation of Suffering and the Path leading to the Cessation of Suffering. It plays a major role in the course of purification. However, early Buddhist teaching of right view avoids every kind of grasping or clinging. Therefore, right understanding may refer to what is meant by sammā ditthi. Indeed, a right or wrong view is a psychological term which explains the internal sources of human behaviour. Right view or wrong view is the basis of one’s personality. A person’s view is directly tied with the faculties of sense, mind, thinking, memory and behaviour. Cognitive psychology is the branch of psychology that studies mental processes including how people think, perceive, remember and learn. As part of the larger field of cognitive science, this branch of psychology is related to other disciplines including neuroscience, philosophy and linguistics. Therefore, my research will review the ethical and cognitive aspects of the Right View in Theravada Buddhist teachings and show its relevance to self-transformation as understood in Buddhism. This is primarily a textual study. The Tipitaka, specially the Sutta Pitaka and the Abhidhamma Pitaka were used as primary sources. For further elucidation and for supporting evidence commentaries were consulted. The Visuddhimagga, though a late compilation, because of the high esteem in which it is held in the Theravāda tradition, was also be utilized in the investigation. In addition,, relevant secondary literature on psychology was also used. The Buddha’s teaching could be analyzed with a view to understanding suffering and the cessation of suffering (dukkha and nirodha). The Buddhist term Sammā Ditthi (Right View), mentioned under the fourth truth called the Noble Path has already been explained in various contexts of the Pāli Canon and Commentaries. I argue that this has ethical and cognitive significance in the process of purification and self-transformation.
A retrospective study on dirofilariasis in five districts in Sri Lanka
(The University of Peradeniya, 2013-07-04) Iddawela, W. M. D. R.; Adicarum, D. R. S.; Ranaweera, R. L. A. R.
Dirofilaria repens is the most important cause of human dirofilariasis in Sri Lanka. It occurs commonly in adults except in Sri Lanka, where children younger than nine years are likely to be infected. The present study was carried out to describe the patient and parasitic factors associated with human dirofilariais in Sri Lanka. A retrospective descriptive study was conducted in 80 samples of worms, referred by surgeons in Badulla, Kandy, Kegalle, Monaragala and Polonnaruwa during the past five years. Data on age, sex and site of lesion were obtained from the details given in the referral letters. Morphological identification of the worm was based on the maximum width, length and the characteristic cuticle with sharp longitudinal cuticular ridges. Sex of the worm was determined by the width, length and distance between anterior end and genital opening. The age of the patients ranged from 8 months to 60 years. Of the study group, 69% were less than 40 years of age and 50.7% were males. Out of 80 patients, 34.5 %( 27) of the patients were less than 10 years of age. The youngest patient was 8 months. The majority (46%) of the patients were from the Kandy district. Nodules were reported in the abdominal wall (2), eye (35), face (4), foot (4), hand (3), leg (3) and scrotum (24). The largest proportion (65/80) were subcutaneous nodules. The adult worm was found in the upper part of the body in 85.6%, eye being the commonest site (41%). The scrotum was the commonest site in the lower part of the body (23.9%). Out of all adult worms, 80.8% were females while 11.5% were male worms. Only one nodule in the eye had both male and the female worms. The average lengths of the female and male worms were 12.1cm and 7.47cm, and average widths of female and male were 478.3 cm and 405.6 cm respectively. In conformity with these morphological characteristics, the filarial worms identified in these patients were Dirofilaria repens. The active age group (< 40 years) was the most affected. There was no difference in incidence between the two sexes. This pattern was seen in the studies done in the last decade of the 20ᵗʰ century. Sri Lanka is an endemic focus of human dirofilariasis due to D. repens. Therefore, dirofilariasis should be included in the differential diagnosis of patients presenting with subcutaneous nodules at any site of the body.
Prevalence of dyspepsia and associated factors among undergraduates of the University of Peradeniya
(The University of Peradeniya, 2013-07-04) Pathirathna, M. L.; Kumarasiri, P. V. R.
Dyspepsia is a disorder of digestive function characterized by discomfort or heartburn and nausea. The incidence of dyspepsia is increasing unacceptably. Very few studies have been conducted in Sri Lanka to determine the prevalence of dyspepsia. The aims of this study were to determine the prevalence of dyspepsia and known associated factors among undergraduate students of the Faculty of Allied Health Sciences, Faculty of Arts and Faculty of Agriculture at the University of Peradeniya. This is a descriptive study, conducted using the simple random sampling method. Data was obtained from hundred students from three faculties who fulfilled inclusion and exclusion criteria. A self- administered questionnaire was used to gather information about upper abdominal symptoms, risk factors and treatment options for dyspepsia. Ethical clearance was obtained from the ethical committee, Faculty of Medicine, University of Peradeniya. Informed written consent was obtained from the participants. Data was entered into a Ms Excel 2007 worksheet and analyzed using standard statistical methods. Prevalence of dyspepsia among undergraduates in the Faculties of Allied Health Sciences, Arts and Agriculture was 71%, 45% and 33% respectively. A significantly higher prevalence of dyspepsia (P<0.002) among undergraduates in the Faculty of Allied Health Sciences was observed compared to the other two faculties. Female students showed a higher prevalence of dyspepsia than male students of the three faculties, and it was found to be 55% and 45% respectively. There was no statistically significant difference between the prevalence of dyspepsia among male and female undergraduates (p> 0.05). The reported prevalence of known associated factors of dyspepsia were; use of some medications 12.8%, stress 49%, hypersensitivity or allergies to food 22.1%, consumption of alcohol 14.8%, cigarette smoking 7.4%, excessive use of coffee and/or tea 26.2% and delaying meals 58.4%. Consumption of spicy foods, acidic foods and fatty foods were found to be at 63%, 52.3% and 76.5% respectively. Epigastric discomfort, burning sensation in the stomach, heartburn and nausea were the most prominent symptoms identified among dyspeptic students. Psychological stress due to exams and high workload, consumption of spicy, fatty and acidic foods and missing and delaying meals are the main contributing factors identified among undergraduate students.
Minimal mahler measure of an algebraic integer In a quadratic field
(The University of Peradeniya, 2013-07-04) Dissanayake, R. M. S.; Ishak, M. I. M.; Perera, S. P. C.
The Mahler measure of a polynomial with integer coefficients is defined as the product of the absolute value of the leading coefficient and the absolute values of the roots of the polynomial that are outside the unit circle. If α is a nonzero algebraic number, that is, a root of an irreducible polynomial with integer coefficients then the Mahler measure of α is defined to be the Mahler measure of a polynomial. An algebraic integer is defined as a root of an irreducible polynomial with integer coefficients and leading coefficient one. This paper presents the derivation of the smallest possible value of the Mahler Measure M(α) for an algebraic integer α that lies in the quadratic field Q (√m) where m is a square free integer. In 1933, D. H. Lehmer posed his famous question referred to in the literature as Lehmer’s conjecture on Mahler measure of a polynomial with integer coefficients. This famous problem, questions the existence of a nonzero algebraic number α such that M (α)<1+ ε for every ε > 0, where α is not a root of unity. Also, Lehmer found that the smallest value of Mahler measure M(α) larger than one, associated with the roots of irreducible polynomial f(x)= 1+x³-x⁴-x⁵-x⁶-x⁷+x⁹+x¹⁰ was M(α) =α₀=1.17628... where α₀ is the largest real root of the above polynomial.
Impact of vulnerability on flood risk in the Nilwala river basin in Sri Lanka
(The University of Peradeniya, 2013-07-04) Nandalal, K. D. W.; Jayaweera, P. S.
Flooding has been one of the most costly disasters in terms of both property damage and human casualties in Sri Lanka. Floods are observed frequently along the Nilwala river in southern Sri Lanka and thus the government is compelled to spend a large amount of national funding for relief work during such floods. Population density, dependency, building conditions, economy, road network and land use are considered to be important vulnerability factors that contribute to the risk due to floods in the Nilwala river basin. Usually, decisions on the mitigation of impacts due to floods before, during and after flood events are taken at the lowest administrative level in the country, which is the Grama Niladari Division (GND) level. This study investigates the impact of vulnerability factors on the risk due to floods at the GND level. Software HEC-GeoRAS and HEC-RAS were used in the determination of flood hazards at the GND level. Inundation area and inundation depth were taken as hazard factors. Flood risks (Equation 1) were calculated and risk level maps were prepared at the GND level using the hazard factors and vulnerability factors mentioned above. Risk = Hazard x Vulner ability (1) The maximum vulnerability value is found to be associated with the economy, followed by land use and road network. Identification of the most effective vulnerability factor using the proposed methodology will be very useful for decision makers to make correct decisions on the allocation of funds for flood mitigation work.
Work-life balance of middle level managers in agro-based organizations in Sri Lanka
(The University of Peradeniya, 2013-07-04) Kumara, S. M. S. P.; de Silva, Saliya
Work-life balance (WLB) is achieving a balance between work life and family life. It is one of the emerging issues in the present day organizations. Increased demand for work and family responsibilities is attributed to high work-life imbalance. According to the literature, high work-life imbalance is associated with occupational stress, low productivity, high absenteeism and turnover of employees. This research was conducted to determine the economic, psychological, physical and spiritual factors affecting the WLB of middle level managers in agro-based organizations. The study was a cross-sectional sample survey conducted with 82 middle level managers from 10 large scale agro-based private companies in Sri Lanka. The respondents were selected using the simple random sampling technique. Primary data were collected mainly using a self-administered questionnaire. Regression analysis was performed to identify the factors affecting WLB of middle level managers. The majority of managers in the sample were males (75%) and most of them were married (85%). The majority of the managers had tertiary-level educational qualifications (diploma – 13%, graduate – 26%, postgraduate – 24%, professional – 21%), while 16% had only GCE (A/L) qualifications. Regression analysis revealed that occupational stress, participation in religious activities, work involvement and level of education affect the WLB of middle managers in the selected agro-based organizations (R²=0.510). Managers with low WLB had high occupational stress and high work involvement. A high WLB could be observed among managers having better education and high religious propensity. The results also revealed that WLB is not associated with age, gender and civil status of the middle managers. The relationship between WLB and non-communicable health disorders (e.g. blood pressure, diabetes, and depression), which are assumed to be associated with work stress, was not significant. Based on the findings, it is concluded that WLB of middle managers could be achieved by managing work related stress and work involvement, while spending time on religious activities. Paying a balanced attention for both family responsibilities and job duties, introducing flexible work schedules, and conducting educational programmes on WLB in agro-based organizations will improve the WLB of the middle level managers.
What factors motivate teachers to select teaching as a career ?
(The University of Peradeniya, 2013-07-04) Panditharatne, Priyani; Wijesundara, Subhashinie
Previous research has identified three categories of motives as being important i.e. extrinsic, intrinsic and altruistic motives in choosing teaching as a career. However, other factors behind this career choice have not been systematically studied in Sri Lanka. Therefore, this study aims to examine the nature of motivation of Sri Lankan teachers in selecting teaching as their career. The objectives of the study were to identify the factors that motivate teachers to select this profession as their career and to develop insights about ways of improving the level of motivation of teachers in schools. The sample consisted of 700 teachers randomly selected from 50 government schools in the Kandy district. Data were collected through a questionnaire survey, which included both closed and open ended questions. The response rate of the questionnaire was 72.4%. There were two parts in the questionnaire. In the first part, seven orientations to teaching factors scale and one future career expectation item were included. The responses were analysed using percentages. The second part of the questionnaire included open ended questions that focused on motivational factors which made teachers select this profession as their career. The responses were analysed using the constant comparison method. Only 33% of the respondents indicated that they always wanted to become teachers whereas 54% of teachers stated that teaching was not their first career choice. Therefore, it can be inferred that the majority of teachers who participated in this study were not really interested in teaching as a career path. Twenty three percent of the respondents indicated that they thought teaching would fit well with their family commitments and 10% of the sample indicated that both the salary and the teaching hours did not influence them. Although teaching was not their first choice of career, 63% of respondents would prefer to select teaching again, if they were given another chance. It also emerged in this study that teacher motivation depends critically on effective school management. Based on the above findings, it can be concluded that the motives of Kandy district teachers to become teachers may include their personal characteristics, intrinsic values and external factors. Implications of these findings for teacher recruitment, teacher management and further research are discussed in the paper.
Variation of steady state infiltration rate with land use type
(The University of Peradeniya, 2013-07-04) Sulakxan, K.; Lavaniyan, S.; Samsen, C. A.; Nandalal, H. K.
The infiltration characteristics of soils under three different land use practices were studied in the premises of the University of Peradeniya, Sri Lanka. The land use practices considered were: turf area, forest area and shrub area. The study aimed at examining the effect of various land use types on infiltration and determining the degree of relationship between infiltration rates and selected soil properties under different land use types. The soil properties selected were initial moisture content, and results of sieve analysis test and Proctor compaction test. These results were used to determine the level of compaction and soil type. The experiment was arranged randomly in selected land use areas and was replicated thrice. The infiltration rates of the soils were measured using a double-ring infiltrometer. The soil samples from these areas were analysed for selected soil properties. It was found that the soil type of all these places was sandy clay loam. The results showed that forest area had the highest average infiltration rate of 31-48 cm/hr while the turf area experienced the least infiltration rate of 14-27 cm/hr; the infiltration rate in shrub area was 30-35 cm/hr. A negative correlation was found between the level of compaction and infiltration rate. Initial moisture content had less influence on steady infiltration rate and it only changed the time to reach the steady infiltration rate.
Validation of candidate genes for salt tolerance in rice by real-time PCR
(The University of Peradeniya, 2013-07-04) Zahra, A. R. F.; De Costa, D. M.; De Costa, W. A. J. M.
Salinity tolerance is a key trait for increasing and stabilizing rice production in salinity prone rice lands worldwide. Identification of the genes responsible for salinity tolerance and quantifying their expression would be useful for developing salt tolerant rice varieties. A previous study conducted by us identified several genes which are responsible for salt tolerance during Phase I (osmotic stress) and Phase II (ionic stress) of salt stress development in the known salt tolerant Sri Lankan rice variety At354. Real-time PCR (qPCR) is a rapid and quantitative method which can be used to quantify the expression levels of candidate genes of salt tolerance. These validated candidate genes for salt tolerance could be identified as genes, which have the potential to be used in the development of salinity tolerant plants through molecular breeding. In the present study, three candidate genes OsPHI-30 (homology to a putatively expressed salt-tolerant gene of rice), OsPHI-147 (homology to putative Serine Decarboxylase) and OsPHI-194 (homology to AP domain DRE binding factor) were quantified and validated by qPCR for their salinity tolerance during Phase I of salt stress development. qPCR was carried out with a MiniOpticon qPCR Detection System (BIORAD Laboratories Inc.) with cDNA of salt-treated and non-salt treated (control) plants obtained from Phase I targeting the candidate genes for salt tolerance, harboured in the cDNA clones (i.e. OsPHI-30, OsPHI—147 and OsPHI-194) and for the reference gene (α-tubulin) using SYBR green dye. The relative quantification values for each target gene were calculated by the standard curve method. Relative fold expression levels of all three genes tested showed increases in salt- stressed At354 relative to the unstressed control. OsPHI-147 (Putative Serine Decarboxylase) showed the highest increase in the gene expression level over the control. These findings of increased expression levels confirmed the up-regulation of the selected candidate genes under salt-stress in the known salt-tolerant Sri Lankan rice variety At354. Therefore, quantitative expression analysis of the cDNA clones OsPHI-30, OsPHI-147 and OsPHI-194 during Phase I of salt stress development by qPCR validated the contribution of these genes to tolerate osmotic stress during Phase I. Furthermore, our results revealed that these validated candidate genes for salt tolerance could be identified as genes, which have the potential to be used in over-expression studies to develop salinity tolerant plants through molecular breeding.
Variation of expression profiles of a defense- related gene transcript (gamm glutamyl transferase) among dessert - and cooking-type
(The University of Peradeniya, 2013-07-04) Basnayake, B. M. P. V.; Kumara, U. M. A.; De Costa, D. M.
Anthracnose, caused by Colletotrichum musae is an economically significant postharvest disease of banana. A variation in the degree of anthracnose development among varieties of banana grown in Sri Lanka has been identified by previous studies conducted in our laboratory. The objective of the present study was to compare the level of expression of a selected gene transcript (homologous to Gamma glutamyl transferase, GGT), identified as an up-regulated gene due to C. musae infection in six varieties of banana, using the relative Reverse Transcriptase Polymerase Chain Reaction (RT-PCR). Mature unripe banana fruits were selected to represent resistant (i.e. Alukesel), moderately resistant (i.e. Seenikesel), moderately susceptible (i.e. Embul and Embun) and susceptible (i.e. Kolikuttu and Suwandel) varieties with respect to postharvest anthracnose development. A set of banana fruits from all six varieties were inoculated with C. musae and another set of fruits were maintained as a control treatment, without inoculating with C. musae. Total RNA was isolated separately from inoculated and non-inoculated fruit peels of the six varieties, one hour after inoculation (1hr AI) and 48 hours after inoculation (48 hr AI)). The RNA extracted from all combinations (banana varieties x treatments x time intervals) were subjected to cDNA synthesis and RT-PCR was performed separately using specific primers for GGT and Actin. Expression of the Actin gene was used as the reference gene for normalization of data when calculating the relative gene expression. Forward and reverse primers for the reference gene were 5’-GAG AAG ATA CAG TGT CTG GA-3’ and 5’-ATT ACC ATC GAA ATA TTA AAA G-3’respectively. Primers for the GGT transcript were designed based on the sequence information of the cDNA clone harbouring the GGT transcript (i.e. Ma SINI 185) using Primer 3 software. The primer sequences were 5’-TAT GGA AGA CCC TTG GAT-3’ and 5’-CAC TTT CTT CCA TGG CAC CT-3. The PCR products obtained for different banana varieties at the two time intervals after inoculation were electrophoresed on 2% agarose gels and signal intensities of PCR products were analyzed by US Scan IT-gel software. Relative RT-PCR of each sample (i.e. variety x time interval combination) was calculated by dividing the expression of gene of interest (GGT transcript) by the expression of the reference gene (Actin). Relative expression of GGT showed considerable variation among different varieties of banana. Based on relative RT-PCR analysis, the rate of GGT expression increased rapidly at the early phase of infection by C. musae (1 hr AI) in varieties Seenikesel, Suwandel and Kolikuttu in comparison to the other three varieties. In contrast, varieties Embun, Embul and Alukesel showed comparatively higher levels of GGT gene expression at a later stage of infection (48 hr AI). Elucidation of expression profiles of a range of defense-related genes would be useful to understand the genetic background of resistance possessed by different varieties of banana.
The utilization and appropriateness of resources, facilities and services of the medical library, University of Peradeniya
(The University of Peradeniya, 2013-07-04) Perera, P. A. S. H.
The objective of the study was to investigate the appropriateness of the resources, facilities and services of the Medical Library, the extent of usage of the same and to identify areas for further improvement. A questionnaire was utilized to survey the study population which consisted of all the undergraduates (1471) and entire academic staff (134) of the two faculties of Dental Sciences and Medicine. Short time users (postgraduates and extended faculty staff) were excluded. The percentage of responses to the questionnaire was 91% out of which undergraduates were 98% and academic staff was 2%. Thus, the response rate of the academic staff cannot be considered a reasonable representation of the group. Therefore, the discussion and conclusions are based only on the responses received from undergraduates. During the period of study, the total number of visitors to the library was 6312 and average number of visitors per day was 82 on week days and 23 on holidays. 98% of these visitors were undergraduates. The purpose of the visits of 44% was for reference work and for reading notes. Photocopying facility was used most by the undergraduates (96%) and books in Clinical Medicine were the most in demand to be photocopied during the period of study. The Medical Library was very important as a resource center for 56% of the respondents. Fifth and first year undergraduates used the library occasionally while 2nd - 4th year undergraduates used it very often. 64% of the respondents were satisfied with library facilities for teaching and learning purposes. While 38% of them were neutral, 36% were satisfied about library facilities for research needs. 44% of undergraduates considered the library collection as comprehensive. Lending and reference sections were the popular areas. Only 18% of undergraduates read current journals. Discussion rooms had not been used by 56% of the respondents. 51% of undergraduates were satisfied about issues regarding library staff. Regarding undergraduates 56% had not used the journals, 66% had not used online databases available through the library webpage and 59% had not used Inter-Library-Loan facility. 38% of the respondents suggested improvements on control of temperature level, quality of the photocopy service, electronic operating system, discussion rooms, availability of computers, disturbances inside the library and toilet facilities. In conclusion, the facilities in the medical library offered to undergraduates could be improved according to the needs identified above.
Using school based assessment to improve teaching and learning
(The University of Peradeniya, 2013-07-04) Iddamalogoda, I. A. D. V. R.; Karunaratne, S.
This study was carried out to determine the students, teachers and educators perception of the School-Based Assessment (SBA) programme which was introduced to the Sri Lankan education system in 1998, and to find out how to implement lessons effectively with different assessment tools to a classroom. A questionnaire was administered to fifty (n=50) randomly selected teachers who teach science for tenth and eleventh graders in Kandy district schools. Informal interviews were carried out with the students, teachers and educators to find out their perception about SBA. As the second stage of the study, 34 lessons taken by 7 of the 50 teachers. Who responded to the questionnaire were observed. Out of the seven teachers four taught in a girls school and the other three taught in a boys school. Both the schools were in the Gampola education zone. The teachers were allowed to use their usual teaching methods and their lessons were observed to find out whether they used different assessment tools to assess the students. As the third step, twelve lesson plans were prepared with different assessment tools for unit 4, “Engages in prevention of diseases associated with the main systems of the human body” of grade ten science. These lessons were implemented to a grade ten classroom in the girls school with the help of the teacher. A teacher who had negative attitudes towards SBA gradually changed her attitudes after the unit was implemented. She was convinced that SBA could be applied effectively to improve teaching and learning after implementation because she was able to see very satisfactory student participation during the implemented unit. Other than that she was able to observe that student skills and attitudes about learning changed positively. The informal interviews with the teachers revealed that the teachers need more support from the education officers to improve their knowledge about the practice of SBA. The education officers accept that SBA is very effective in the teaching-learning process but it is not applied in the expected manner in Sri Lankan classrooms as priority is given for passing examinations. The study revealed that SBA is an effective method to improve teaching and learning. There should be training programmes for teachers that would help to change their negative attitudes towards the practice.
The use of information communication technology by undergraduates of the Faculty of Dental Sciences, University of Peradeniya
(The University of Peradeniya, 2013-07-04) Alahakoon, C. N. K.
The main objective of the study was to investigate ICT awareness and ICT skills among 2nd and 3rd year undergraduates of the Dental Faculty, University of Peradeniya. Other objectives were to examine the types of ICT services used by undergraduates (such as the Online Public Access Catalogue (OPAC), and webOPAC); to identify techniques used to search for information; to identify the purposes of using the Internet; and to identify obstacles faced by undergraduates when accessing ICT services in the library. A semi-structured questionnaire was used to collect data. A Hundred and fifty questionnaires were administered. The majority of the respondents were females. Although the library has the OPAC, only 7.9% of the students use it. Seventy three percent of students prefer the Card Catalogue. Of the 2nd years students 20 (17.5%) said that ICT facilities provided for them were adequate, but 22.8% of the 3rd years indicated that the facilities provided were inadequate to fulfil their information needs. Regarding the use of search techniques, 47.68% of the 2nd year students and 50.83% of the 3rd year undergraduates said they do not use the search tools available with the OPAC. A majority of these students also said that they were not aware of these library services. Regarding the search engines, 74.1% of 2nd years and 75% of 3rd year undergraduates said they used Google. Yahoo was used by about 44.4% and 41.7% of 2nd and 3rd year students, respectively. Third year students used the Internet to find e-journals and to browse the web. The Dental Faculty and Library Services of the University of Peradeniya should consider the following recommendations: They should pay more attention to improving ICT usage among students and promote ICT services. More attention should also be paid to the content of the library orientation programme. The Computer Aided Lab (CAL) unit should be equipped with more computers and should be updated with necessary software. A library awareness programme should be introduced and a faster Internet facility should also be established.
Usage technology in science teaching and learning in Sri Lanka: can the mobile phone be ideal ?
(The University of Peradeniya, 2013-07-04) Ekanayake, T. M. S. S. K. Yatigammana
Integration of Information Communication Technology (ICT) enhances the effectiveness of science teaching and learning. Recent research suggests that both the functions and the attributes of mobile phones can support science teaching and learning processes since they offer a variety of facilities. Thus they may render opportunities such as collaborative, contextual and authentic learning, to students while connecting the classroom with the outside world. In Sri Lanka ICT integration into science teaching and learning is not common due to the lack of ICT resources in schools. Even though mobile phones are cheap, common, and teenagers are well aware of its functions, mobile phones are not yet introduced into Sri Lankan schools as a teaching or learning tool. Therefore, the focus of this study is to investigate whether mobile phones can be integrated into Sri Lankan schools in order to enhance the effectiveness in science teaching and learning. The current study used the mixed method approach. First, Sri Lankan teachers’ readiness to use mobile phones in teaching was assessed focusing on one province in Sri Lanka. A survey questionnaire of 200 science teachers and follow-up interviews with 18 deliberately selected teachers were used in this process. Then a Continuous Professional Development (CPD) Workshop was carried out for these 18 teachers. During this, the teachers developed four science lessons where mobile phones were integrated and these lessons were subsequently implemented in four real classroom settings. Finally, the teachers were brought together for a Review Workshop to discuss their views and experiences in using mobile phones in science teaching and learning. During the workshops and lesson implementation, data were collected through observation using audio, video recordings and field notes. The data collected from the CPD workshop and lesson implementations were analysed using thematic analysis with the help of NVivo8 qualitative data analysis software. The findings show that the functions and attributes of a mobile phone provided support for science teaching and learning during planning, implementation and evaluation stages of a lesson. Particularly, it was found that the camera function was useful during the planning and implementation stages of science lessons. Further, the Bluetooth device enabled the teacher and students to share the learning materials free of charge, during the planning stage. The main limitation of this study was the selection of participants from a single province in Sri Lanka. Furthermore, these results are based only on four lessons. Thus, further studies need to be carried out with a greater number of participants and in different contexts before making broad generalizations.

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