Science
Permanent URI for this communityhttp://repository.kln.ac.lk/handle/123456789/1
Browse
14 results
Search Results
Item 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.Item Ancient Reservoirs of Sri Lanka: A Modern Biological Resource for Assuring Food Security in Rural Communities(University of Kelaniya, 2005) Kularatne, M.G.; Amarasingha, U.S.Reservoir construction in Sri Lanka dates back to times even before the period of written history. In Sri Lanka (64,652 km2), there are over 200 large (750 – 7,793 ha) and medium-sized (250 – 750 ha) reservoirs with a cumulative extent of over 130,000 ha, which support capture fisheries. In addition, there are over 15,000 small (<50 ha) village reservoirs with a total extent of about 39,000 ha. The reservoir density in Sri Lanka (about 2.6 ha for every km2 of island) is one of the highest, if not the highest in the world. Almost entire reservoir resource in Sri Lanka, with the exception of recently constructed hydroelectric reservoirs, supports agricultural food production in the country. As the extent of perennial reservoirs in each district is directly related to per capita freshwater fish consumption, in addition to agricultural production, major perennial reservoirs of Sri Lanka support animal protein production in the form of fish production. This is of particular importance because marine fish consumption is much low in inland districts possibly due to the availability of good quality freshwater fish locally. Also, there is a significant potential for the development of culture-based fisheries in small, village reservoirs of the country. An average fish yield of about 450 kg ha-1 can be achieved during a single culture cycle within a year from the culture-based fisheries in these village reservoirs. However, in order to achieve success of this strategy, a strong extension mechanism is needed to obtain active community participation. As inland fishery is a source of relatively cheap animal protein for rural communities, future prospects of this sector for food security need to be properly understood to give a high priority for inland fisheries research and development in national development plans.Item Monitoring eutrophication trends in Bolgoda North Lake, Sri Lanka by Satellite Remote Sensing(Central Fisheries Research Institute (CFRI) Trabzon, Turkey in cooperation with Japan International Cooperation Agency (JICA), Japan, 2016) Dahanayaka, D.D.G.L.; Perera, B.D.C.; Wijeyaratne, M.J.S.; Tonooka, H.This study was aimed to determine the present level and past trends of eutrophication of the Bolgoda North lake, Sri Lanka using in situ Chlorophyll-a (Chl-a) measurements and remote sensing data obtained from Advanced Space-borne Thermal Emission and Reflectance Radiometer (ASTER) satellite data. From March to October 2013, Chl-a, nitrate and phosphate contents of the lake were measured once a month on the days of ASTER overpass and using standard laboratory methods. Cloud-free ASTER images of the lake for the 2000-2013 period were atmospherically corrected using Fast Line-ofsight Atmospheric Analysis of Hypercubes (FLAASH) and in-situ Chl-a data were regressed with atmospherically corrected three ASTER Visible and Near Infrared band ratios of the same date. The green/red band ratio, which had the highest coefficient of determination, was used to develop algorithm for generation of 15-m resolution Chl-a distribution maps. Results indicated that eutrophication of this lake has increased from 2008 to 2011. Heavy eutrophic conditions were noted in several regions of the lake in 2013, especially in water stagnant areas and adjacent to freshwater inlets. Unplanned urbanization and inadequate facilities for waste management have resulted in heavy eutrophication of the water body. If the present trends of waste disposal and unplanned urbanization continue, enormous environmental problems would be resulted in future.Item New species of the Pristomyrmex profundus Wang group from the Oriental Region (Hymenoptera: Formicidae: Myrmicinae)(2016) Yamane, S.; Dias, R.K.S.Two new species of the ant genus Pristomyrmex Mayr belonging to the P. profundus Wang group are described from the Oriental Region: P. leleji Yamane et Dias, sp.n. from Thailand, and P. sinharaja Dias et Yamane, sp.n. from Sri Lanka. A key to species of the Pristomyrmex profundus group is presented.Item External Quality Assessment of Higher National Diploma Programmes Offered in Sri Lanka: An Account of Best Practices(South Eastern University of Sri Lanka, 2013) Bandara, T.H.S.S.; Wijeyaratne, M.J.S.Quality assurance activities that are carried out in the Sri Lankan university system since 2002 were introduced to the alternative higher education sector in 2010. External quality assessment reviews of Higher National Diploma (HND)programme offered in eleven Advanced Technological Institutes (ATIs) located in different regions of the country were carried out to identify the best practices, strengths and weaknesses and make suitable recommendations to improve the quality of those programmes. The aspects reviewed were curriculum design, content and review; teaching, learning and assessment methods; quality of students, their progress and achievements; use of student feedback; peer observation; skills development; and academic guidance and counseling. The objective of the present study was to determine whether there are regional differences among ATIs when best practices that are in place in different HND programmes are considered. Best practices identified by the reviewers in external quality assessment review reports of HND programmes in Accountancy, Agriculture, Business administration, English, Information Technology and Management conducted in Ampara, Dehiwala, Jaffna, Kandy, Kegalle, Kurunegala, Labuduwa and Trincomalee ATIs were analysed using Principal Component Analysis to determine whether there are regional differences among ATIs with respect to best practices that are in place in each programme. Results indicated that the good practices identified by reviewers in different HND programmes do not depend on the location of the ATI, the ethnicity of the majority community and prevalence of deterrent factors such as armed secessionist conflicts in the area. Differences in the resources available and the motivation and dedication of the staff may have contributed to the differences in the good practices that are in place in different ATIs.Item Modulation of ethoxyresorufin O-deethylase and glutathione S-transferase activities in Nile tilapia (Oreochromisniloticus) by polycyclic aromatic hydrocarbons containing two to four rings: implications in biomonitoring aquatic pollution(Ecotoxicology, 2010) Pathiratne, A.; Hemachandra, C.K.Despite ubiquity of polycyclic aromatic hydrocarbons (PAHs) in the tropical environments, little information is available concerning responses of tropical fish to PAHs and associated toxicity. In the present study, effects of five PAHs containing two to four aromatic rings on hepatic CYP1A dependent ethoxyresorufin O-deethylase (EROD), glutathione S-transferase (GST) and serum sorbitol dehydrogenase (SDH) activities in Nile tilapia, a potential fish species for biomonitoring pollution in tropical waters, were evaluated. Results showed that EROD activities were induced by the PAHs containing four aromatic rings (pyrene and chrysene) in a dose dependent manner. However PAHs with two to three aromatic rings (naphthalene, phenanthrene and fluoranthene) caused no effect or inhibition of EROD activities depending on the dose and the duration. Fluoranthene was the most potent inhibitor. SDH results demonstrated that high doses of fluoranthene induced hepatic damage. GST activity was induced by the lowest dose of phenanthrene, fluoranthene and chrysene but high doses had no effect. The results indicate that induction of EROD enzyme in Nile tilapia is a useful biomarker of exposure to PAHs such as pyrene and chrysene. However EROD inhibiting PAHs such as fluoranthene in the natural environment may modulate the EROD inducing potential of other PAHs thereby influencing PAH exposure assessments.Item Species composition and abundance of littoral oligochaete fauna in Lunuwila reservoir, Sri Lanka(International Review of Hydrobiology, 2000) Weerasundara, A.; Pathiratne, A.; Costa, H.H.Item Limnology and culture-based fisheries in non-perennial reservoirs in Sri Lanka(Lakes & Reservoirs: Research & Management, 2005) Jayasinghe, U.A.D.; Amarasinghe, U.S.; de Silva, S.S.This study was carried out to investigate the possibility of using the limnological characteristics of non-perennial reservoirs in Sri Lanka for the future management of culture-based fisheries. Forty-five reservoirs were randomly selected to study their limnology, out of which 32 were stocked with fish fingerlings of Chinese and Indian carps, tilapia and freshwater prawn at stocking densities ranging from 218?4372 fingerlings ha?1. Of these, 23 reservoirs were harvested at the end of the culture period (6?10 months). Thirteen limnological parameters were measured during the water retention period of each of the 45 reservoirs between November 2001 and January 2004. The mean values of the limnological parameters were used to ordinate the reservoirs through principal component analysis. Ordination showed a productivity gradient among reservoirs where Secchi disc depth, total phosphorus, chlorophyll-a, inorganic turbidity and organic turbidity were identified as key factors. The total fish yield of culture-based fisheries was positively correlated to the scores of the first principal component axis. This study reveals that it is possible to classify non-perennial reservoirs in Sri Lanka based on the above limnological parameters in order to develop culture-based fisheries and that they could be applicable in comparable water bodies elsewhere in the tropics.Item Some aspects of photosynthetic characteristics in a set of perennial irrigation reservoirs located in five river basins in Sri Lanka(Hydrobiologia, 2002) Silva, E.I.L.; Amarasinghe, U.S.; de Silva, S.S.; Nissanka, C.; Schiemer, F.Phytoplankton primary productivity of eleven irrigation reservoirs located in five river basins in Sri Lanka was determined on a single occasion together with light climate and nutrient concentrations. Although area-based gross primary productivity (1.43?11.65 g O2 m?2 d?1) falls within the range already established for tropical water bodies, net daily rate was negative in three water bodies. Light-saturated optimum rates were found in water bodies, with relatively high algal biomass, but photosynthetic efficiency or specific rates were higher in water bodies with low algal biomass, indicating nutrient limitation or physiological adaptation of phytoplankton. Concentrations of micronutrients and algal biomass in the reservoirs are largely altered by high flushing rate resulting from irrigation release. Underwater light climate and nutrient availability control the rate of photosynthesis and subsequent area-based primary production to a great extent. However, morpho-edephic index or euphotic algal biomass in the most productive stratum of the water column is not a good predictor of photosynthetic capacity or daily rate of primary production of these shallow tropical irrigation reservoirs.Item Impact of Oreochromis mossambicus ? O. niloticus (Pisces: Cichlidae) hybridization on population reproductive potential and long-term influence on a reservoir fishery(Fisheries Management and Ecology, 1996) Amarasinghe, U.S.; de Silva, S.S.Exotic cichlids, introduced to Asia during the second half of the twentieth century, contribute significantly to the reservoir fisheries in the region. The two major cichlid species, Oreochromis mossambicus (Peters) and O. niloticus (L.), tend to interbreed easily. In Sri Lankan reservoirs, introgressive hybridization of these two cichlids takes place. The reproductive biology of O. mossambicus, O. niloticus and their hybrids in three reservoirs in Sri Lanka was evaluated. An imbalance in sex ratio with male dominance was evident. The estimated fecundity for 20-cm fish, using fecundity-total length relationships for various populations, indicated that there was a decline in fecundity in hybrid forms. It is hypothesized that the long-term effect of crosshybridization between the two cichlids might lead to a decline in fish yields in perennial reservoirs of Sri Lanka. The importance of the findings of the present study for the management of the reservoir fisheries in Asia is highlighted.