Browsing by Author "Herath, H."

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Comparison of different RNA extraction protocols: An optimized RNA extraction protocol for tea leaves [Camellia sinensis (L.) O. Kuntze]
(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Keerthika, V.; Ranatunga, M. A. B.; Perera, D.; Herath, H.
Extracting high-quality RNA is critical for downstream applications such as quantitative real time PCR (qRT PCR), RNA sequence based transcriptomics and a prerequisite for ensuring representation of all expressed genes in a cDNA library. Tea is a popular non- alcoholic beverage crop and tissues contain abundant polysaccharides, phenolic compounds and other metabolites, which hinder isolation of high-quality RNA. Tender two leaves and a bud harvested is the economically important tissues of tea. A large number of extraction protocols have been exploited or modified for tea, viz commercial kits, CTAB-based methods and SDS-based methods. However; difficulties were encountered in terms of purity and quantity of isolated RNA, while some of the methods were time-consuming. Hence, the present study was aimed to optimize protocol/s for extracting good quality RNA suitable for downstream applications from two leaves and a bud tissue of tea. Two different RNA extractions protocols based on CTAB and hot borate with modifications along with three commercial RNA extraction kits were used to extract RNA from two tea cultivars. Out of which, a CTAB-based protocol optimized for pomegranate plant tissues with minor modifications resulted in the highest RNA yield, varying from 524 ± 4 to 776 ±16 μg/ml for cultivars TRI 2023 and TRI 2025 and high integrity as confirmed by Gel electrophoresis (distinct and visible 28S rRNA and 18S rRNA bands). The extracted RNA was further used for cDNA synthesis, expression of 18s house keeping gene through Realtime-polymerase chain reaction (qRT-PCR). Results showed that the yield and quality of total RNA extracted were suitable for qRT-PCR, depicting the quality of RNA for the downstream applications. Commercially available extraction kits despite of giving sufficient amount of RNA, had lesser yield and quality when compared to the CTAB based method. The protocol optimized for pomegranate was modified with omitting washing the RNA pellet with LiCl and replacing the extraction buffer (CTAB, PVP, NaCl, EDTA, Tris HCl, Spermidine, β-mercaptoethanol) with extraction buffer used for grapevines. This protocol enables successful isolation of RNA from two leaves and a bud tissues of tea within two days without the use of toxic and expensive chemicals such as phenol, guanidium isothiocyanate and guanidium hydrochloride. The protocol is efficient, simple, and reproducible and is therefore recommended for RNA extraction from plants with high polyphenol contents
Decaying Hardwood Associated Fungi Showing Signatures of Polyethylene Degradation
(BioResources, 2021) Perera, P.; Deraniyagala, A.S.; Mahawaththagea, M.P.S.; Herath, H.; Rajapakse, C.S.K.; Wijesinghe, P.; Attanayake, R.N.
The involvement of wood decay fungi and the importance of their enzymes in polyethylene degradation is well documented. Therefore, decay-resistant hardwood associated fungi should be better degraders with their versatile enzymatic systems. In the current study, decaying hardwood associated fungi were isolated and their ability to degrade low-density polyethylene (LDPE) was assessed. Thirty-three isolates were identified by sequencing the internal transcribed spacer region of nuclear ribosomal DNA. Randomly selected isolates were tested for laccase producing abilities. Three species were selected to test their potentials in LDPE sheet degradation. Fungi were incubated in Czapek-Dox broth containing 20-micron LDPE sheets at room temperature for 60 days. The biodegradation signatures were assessed by analyzing the changes in structural characteristics of LDPE using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), percent reduction of tensile properties, and weight loss. FTIR analysis revealed changes in certain functional groups compared with the control, indicating chemical changes resulting from the treatment. LDPE sheets incubated with fungi showed cracks and holes under SEM analysis, percent reduction in tensile properties, and weight loss, which are the signatures of degradation. This study revealed that the hardwood decaying basidiomycetes, Phlebiopsis flavidoalba, Schizophyllum commune, and Phanerodontia chrysosporium have the potential for in vitro LDPE degradation.
Female entrepreneurial orientation and firm performance: with special reference to Sri Lanka
(Management and Sustainable Development, 2023) Herath, H.
The purpose of this study is to examine how entrepreneurial orientation influences firm performance of female entrepreneurs in Sri Lanka. The proposed conceptual model delineates the direct relationship between innovativeness, proactiveness, risk-taking, autonomy and competitive aggressiveness - the five dimensions of entrepreneurial orientation - and firm performance of female-owned entrepreneurial firms. This study used a randomly selected sample of 267 female-owned entrepreneurial firms in Sri Lanka to test the hypothesised relationships between the constructs; structural equation modelling was performed. The findings of this study confirmed that entrepreneurial orientation has a positive effect on firm performance of female-owned entrepreneurial firms in Sri Lanka. Particularly, findings confirm that all five dimensions of entrepreneurial orientation (innovativeness, proactiveness, risk-taking, autonomy and competitive aggressiveness) have a positive impact on the performance of these firms. Thus, entrepreneurial orientation is a mechanism and a strategy for the success and the survival of female-owned entrepreneurial firms.
Gestational diabetes mellitus and risk of type 2 diabetes 10 years after the index pregnancy in Sri Lankan women—A community based retrospective cohort study
(PLOS ONE, 2017, DOI: 10.1371/journal.pone.0179647 /http://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0179647&type=printable, 2017) Herath, H.; Herath, R.; Wickremasinghe, R.
Background Women with a history of gestational diabetes mellitus (GDM) have an increased risk of type 2 diabetes mellitus (T2DM) later in life compared to women with no GDM. This study was aimed to determine the risk of developing T2DM 10 years after GDM in Sri Lankan women. Methods A retrospective cohort study was conducted in the Colombo district, Sri Lanka. 7205 women who delivered a child in 2005 were identified through Public Health Midwives in the field. Women with antenatal records were interviewed and relevant data were extracted from medical records to identify potential participants. One hundred and nineteen women who had GDM and 240 women who did not have GDM were recruited. Current diagnosis of diabetes was based on history, relevant medical records and blood reports within the past 1 year. Results The mean duration of follow up was 10.9 (SD = 0.35) years in the GDM group and 10.8 (SD = 0.31) years in the non-GDM group. The incidence density of diabetes in the GDM group was 56.3 per 1000 person years compared to 5.4 per 1000 person years in non GDM group giving a rate ratio of 10.42 (95% CI: 6.01–19.12). A woman having GDM in the index pregnancy was 10.6 times more likely to develop diabetes within 10 years compared to women with no GDM after controlling for other confounding variables. Delivering a child after 30 years, being treated with insulin during the pregnancy and delivering a baby weighing more than 3.5 Kg were significant predictors of development of T2DM after controlling for family history of diabetes mellitus (DM), GDM in previous pregnancies, parity and gestational age at delivery. Conclusions Women with GDM had a 10-fold higher risk of developing T2DM during a 10-year follow up period as compared to women with no GDM after controlling for other confounding variables.
Gestational diabetes mellitus and risk of type 2 diabetes 10 years after the index pregnancy in Sri Lankan women-A community based retrospective cohort study
(Public Library of Science, 2017) Herath, H.; Herath, R.; Wickremasinghe, R.
BACKGROUND: Women with a history of gestational diabetes mellitus (GDM) have an increased risk of type 2 diabetes mellitus (T2DM) later in life compared to women with no GDM. This study was aimed to determine the risk of developing T2DM 10 years after GDM in Sri Lankan women. METHODS: A retrospective cohort study was conducted in the Colombo district, Sri Lanka. 7205 women who delivered a child in 2005 were identified through Public Health Midwives in the field. Women with antenatal records were interviewed and relevant data were extracted from medical records to identify potential participants. One hundred and nineteen women who had GDM and 240 women who did not have GDM were recruited. Current diagnosis of diabetes was based on history, relevant medical records and blood reports within the past 1 year. RESULTS: The mean duration of follow up was 10.9 (SD = 0.35) years in the GDM group and 10.8 (SD = 0.31) years in the non-GDM group. The incidence density of diabetes in the GDM group was 56.3 per 1000 person years compared to 5.4 per 1000 person years in non GDM group giving a rate ratio of 10.42 (95% CI: 6.01-19.12). A woman having GDM in the index pregnancy was 10.6 times more likely to develop diabetes within 10 years compared to women with no GDM after controlling for other confounding variables. Delivering a child after 30 years, being treated with insulin during the pregnancy and delivering a baby weighing more than 3.5 Kg were significant predictors of development of T2DM after controlling for family history of diabetes mellitus (DM), GDM in previous pregnancies, parity and gestational age at delivery. CONCLUSIONS: Women with GDM had a 10-fold higher risk of developing T2DM during a 10-year follow up period as compared to women with no GDM after controlling for other confounding variables.
In vitro application of selected essential oils and their major components in controlling fungal pathogens of crown rot in Embul banana (Musa acuminata – AAB)
(International Journal of Food Science and Technology, 2008) Herath, H.; Abeywickrama, K.P.
The necessity for pesticide-free fresh produce have prompted investigating the effect of selected essential oils and their major components on inhibition of conidial germination, appressoria formation and membrane permeability changes of the pathogens responsible for crown rot of banana. Eugenol, which is the major component of the essential oil of Ocimum basilicum, was the most effective chemical component in inhibiting conidial germination of Colletotrichum musae and Fusarium proliferatum in vitro while Cymbopogon citratus oil was the least effective. Both O. basilicum and C. citratus oils and their major components (Eugenol, citral a + b) inhibited appressoria formation by C. musae and changed the selective permeability of conidial membranes. Ocimum basilicum oil, eugenol and citral a + b could be satisfactorily used for inhibition of conidial germination and disruption of conidial activity of banana pathogens
An integrated treatment of basil oil (Ocimum basilicum) and alum with modified atmosphere to control crown rot disease in Embul banana
(2009) Abeywickrama, K.P.; Wijerathna, C.; Herath, H.; Sarananada, K.H.
A study was undertaken with the objective of developing environmental friendly integrated treatment strategies for controlling crown rot disease in Embul banana. The fungicidal potential of 1% alum (sodium aluminium sulphate) was observed in vitro. Findings indicate that alum+basil oil (0.16% or 0.20% v/v) treated 80, 85, 90 day mature Embul banana fruits were relatively free from crown rot dis-ease after subjecting to modified atmosphere packaging (MAP) and storage at optimum temperature. Crown rot disease severity of 85-day mature and vacuum packed 1% alum (w/v) washed banana was lower and comparable to carbendazim (bavistin) treatment. After ripening, there was no significant difference in physico-chemical properties (titratable acidity, total soluble solids, pH, fruit firmness) of all treated fruits compared to the control. Sensory properties were slightly affected as compared to un-treated fruits. MAP and vaccum packaging in combination with alum and/ or basil oil spray treatments at 12-140C could extend the storage life of Embul banana upto 32 days which could be recommended for sea shipment.
Isolation and identification of thermophilic bacteria and cyanobacteria from Maha Oya hot springs in Sri Lanka
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Medhavi, P.I.H.R.; Samarasinghe, D.G.S.N.; Herath, H.
Hot springs are a rich source of thermophilic microorganisms such as bacteria, cyanobacteria and archaea. Though, there are several hot springs recorded in Sri Lanka, a comprehensive community analysis of thermophilic microorganisms in these springs is inadequate. Therefore, the present study was conducted to isolate and identify the thermophilic bacterial and cyanobacterial diversity in Maha Oya hot springs. Water samples were collected from the surface and the bottom of the seven wells of Maha Oya hot water springs, which showed temperatures ranging from 42 to 59.80C and pH ranging from 6.89-7.63. Water samples treated with Lugol’s iodine as well as microbial mats growing on water surface and attached to the surface of wells, were observed under a light microscope to determine the presence of cyanobacteria. Thermophilic bacteria were isolated by inoculating a dilution series (100, 10-2 and 10-4) of water samples separately into nutrient agar medium and incubating at 550C for 48 hours. Water and microbial mat samples were inoculated into cyano-specific BG11 and BG110 media and incubated at 550C and 12:12 hours dark:light cycle to isolate culturable thermophilic cyanobacteria. Based on morphological (colony morphology, Gram staining, endospore staining and motility test) and biochemical (oxidase activity, catalase activity, H2S production, citrate utilization, glucose fermentation) characteristics, the isolated bacteria were identified as Bacillus thermoamylovorans, Meiothermus sp. and Bacillus schlegelii which have been previously reported as thermophiles. Morphological identification of both uncultured and cultured cyanobacteria revealed the presence of eight different cyanobacterial genera. The most abundant genus was Oscillatoria . Additionally, Calothrix, Synechococcus, Gloeocapsa, Gloeothece, Cylindrospermopsis, Lyngbya and Pseudanabaena were observed. The isolation and identification of these thermophiles could be useful in mass scale production of thermostable enzymes and other bioactive compounds with biotechnological and industrial applications.
Knowledge on first aid among non-medical undergraduates of University of Peradeniya
(Faculty of Medicine, University of Kelaniya, Sri Lanka, 2021) Gunarathne, D.; Hemakeerthi, C.; Hashoora, F.; Hemal, H.; GunathiIake, D.; Gunarathne, R.; Chavindra, D.; Geekiyanage, D.; Herath, H.; Gunarathne, K.
Introduction: Knowledge on first aid is paramount in modem day’s world. University students are one of the best group of advocates to spreading knowledge and implementing correct first aid practices in the society. Objectives: To assess the level and adequacy of knowledge among first year undergraduates of University of Peradeniya, to determine whether the knowledge differs by the faculty of study and to determine the sources from which students gained their knowledge on first aid. Methods: A descriptive cross-sectional study was carried out among 239 randomly selected first year undergraduates from 8 faculties in the University of Peradeniya, excluding the Faculty of Medicine. A self-administered questionnaire was used to collect data. The adequacy of knowledge was assessed according to the marks obtained for the questionnaire. Results: Of the participants, 71.4% had adequate knowledge on first aid. There was a significant association between adequacy of knowledge between students and the type of faculty they belong. The adequacy of knowledge in students from faculties related to biology stream was significantly higher than the students from other faculties. (p=0.018) The commonest source of obtaining knowledge on first aid was family and friends. Conclusions: Knowledge on first aid among students from faculties that are not related biology is not adequate. Implementing workshops and training programs on first aid, tailor made to each faculty is recommended to improve the knowledge on first aid.
Policy implementation and recommended actions to create healthy food environments using the healthy food environment policy index (Food-EPI): a comparative analysis in South Asia
(Elsevier Ltd, 2024) Pineda, E.; Atanasova, P.; Wellappuli, N.T.; Kusuma, D.; Herath, H.; Segal, A.B.; Vandevijvere, S.; Anjana, R.M.; Shamim, A.A.; Afzal, S.; Akter, F.; Aziz, F.; Gupta, A.; Hanif, A.A.; Hasan, M.; Jayatissa, R.; Jha, S.; Jha, V.; Katulanda, P.; Khawaja, K.I.; Kumarendran, B.; Loomba, M.; Mahmood, S.; Mridha, M.K.; Pradeepa, R.; Aarthi, G.R.; Tyagi, A.; Kasturiratne, A.; Sassi, F.; Miraldo, M.
BACKGROUND The increasing prevalence of diet-related non-communicable diseases (NCDs) in South Asia is concerning, with type 2 diabetes projected to rise to 68%, compared to the global increase of 44%. Encouraging healthy diets requires stronger policies for healthier food environments.METHODS This study reviewed and assessed food environment policies in Bangladesh, India, Pakistan, and Sri Lanka from 2020 to 2022 using the Healthy Food Environment Policy Index (Food-EPI) and compared them with global best practices. Seven policy domains and six infrastructure support domains were considered, employing 47 good practice indicators to prevent NCDs. Stakeholders from government and non-governmental sectors in South Asia (n = 148) were invited to assess policy and infrastructure support implementation using the Delphi method.FINDINGS Implementation of food environment policies and infrastructure support in these countries was predominantly weak. Labelling, monitoring, and leadership policies received a moderate rating, with a focus on food safety, hygiene, and quality rather than obesity prevention. Key policy gaps prioritized for attention included front-of-pack labelling, healthy food subsidies, unhealthy food taxation, restrictions on unhealthy food promotion, and improvements in school nutrition standards to combat NCDs.INTERPRETATION Urgent action is required to expand food policies beyond hygiene and food security measures. Comprehensive strategies targeting NCD prevention are crucial to combat the escalating burden of NCDs in the region.
Pollen biology and reproductive ecology of selected paleotropical dendrobiums and its commercial hybrids.
(Journal of Pollination Ecology, 2023) De Silva, R.; Herath, H.; Ratnayake, S.; Attanayake, R.; Senanayake, P.
Understanding the reproductive biology is of great importance in the development of novel hybrids in ornamental plants. Pollen fitness-related traits are crucial for the pollination success in any plant species including dendrobiums. The aim of the study was to determine and compare the fitness traits of ten commercial Dendrobium hybrids and two indigenous Dendrobium species, D. crumenatum and D. anosmum found in Sri Lanka. We measured pollen viability, pollen germinability, and fruit production after controlled pollination. The effect of storage temperature on D. crumenatum pollen viability was evaluated to establish a suitable pollen storage method to improve future breeding programmes, as the flowering of dendrobiums is seasonal. The reproductive ecology of selected dendrobiums was studied by the observations of visits of natural pollinators and by assessing floral morphology to predict their potential pollinators. Six commercial hybrids had non- viable pollen while D. crumenatum showed the highest pollen germinability under both in vivo and in vitro conditions. Ninety percent of the commercial hybrids failed in vitro pollen germination whereas under in vivo conditions 50% were successful. Self-incompatibility in D. crumenatum was observed in both hand-pollination and under natural pollination. Pollen of D. crumenatum can be stored for two weeks at 9°C maintaining viability and germinability. Selected dendrobiums have shown adaptations to melittophily, suggesting the pollination by bees. Findings indicated a reduction of male fitness in most of the commercial Dendrobium hybrids and a higher fruit set is seen in selfing than cross-pollination. The present study provides information for developing conservation strategies and future hybridization programmes in paleotropical dendrobiums.
Zinc content and prediction of bio-availability of zinc in some locally grown rice (Oryza sativa L.) varieties in Sri Lanka
(National Science Foundation of Sri Lanka, 2016) Herath, H.; Rajapakse, D.; Wimalasena, S.; Weerasooriya, M.K.B.
Rice is the staple food in Sri Lanka and the country has a large number of traditional and improved rice varieties. Since their zinc content and bio-availability has not been studied systematically, the present study focused on the zinc content in some traditional rice varieties with high demand and also some improved rice varieties, and their predictable bioavailability. Thirty nine rice varieties from Bombuwala and Bathalagoda Regional Agricultural Research and Development Centres, grown during Yala (March - August, 2006) and Maha (September - March, 2006 ⁄2007) seasons were analysed for stable high zinc rice varieties. Mean zinc content (mg/100 g, on dry weight basis) in the varieties from Bathalagoda varied from 2.17 (Masuran) to 4.49 (Wanni Dahanala), while in the varieties from Bombuwala it varied from 2.46 (Bg 352) to 3.71 (Dahanala) with average values of 3.19 ± 0.55 and 3.11 ± 0.32, respectively. Overall mean zinc content (mg/ 100 g, on dry basis) in the two locations varied from 2.51 (Masuran) – 3.91 (Kalu Bala Wee) with an average value of 3.18 ± 0.45. The mean zinc contents varied significantly (p ≤ 0.05) with varieties. A significant variation (p ≤ 0.05) was observed with respect to the site, season, variety, site*var and ses*var in two way ANOVA, while site*ses*var showed a significant variation in three way ANOVA. The reduction of zinc and phytic acid contents in the selected fifteen polished rice varieties (at polishing rate 8 – 10 %) were 18.2 – 60.7 % and 18.8 – 40.8 %, respectively and no significant correlation was observed between zinc and phytic acid. A moderate bio-availability of zinc was shown by the molecular ratio of zinc:phytic acid and these values ranged from 8.3 – 12.5 and 9.3 – 18.9 in brown rice and polished rice, respectively.