Showing papers by "University of Peradeniya published in 2012"

Autonomous Distributed V2G (Vehicle-to-Grid) Satisfying Scheduled Charging

Abstract: To integrate large scale renewable energy sources in the power grid, the battery energy storage performs an important role for smoothing their natural intermittency and ensuring grid-wide frequency stability. Electric vehicles have not only large introduction potential but also much available time for control because they are almost plugged in the home outlets as distributed battery energy storages. Therefore, vehicle-to-grid (V2G) is expected to be one of the key technologies in smart grid strategies. This paper proposes an autonomous distributed V2G control scheme. A grid-connected electric vehicle supplies a distributed spinning reserve according to the frequency deviation at the plug-in terminal, which is a signal of supply and demand imbalance in the power grid. As a style of EV utilization, it is assumed that vehicle use set next plug-out timing in advance. In such assumption, user convenience is satisfied by performing a scheduled charging for the plug-out, and plug-in idle time is available for the V2G control. Therefore a smart charging control is considered in the proposed scheme. Satisfaction of vehicle user convenience and effect to the load frequency control is evaluated through a simulation by using a typical two area interconnected power grid model and an automotive lithium-ion battery model.

Mesenchymal-epithelial transition (MET) as a mechanism for metastatic colonisation in breast cancer

Abstract: As yet, there is no cure for metastatic breast cancer. Historically, considerable research effort has been concentrated on understanding the processes of metastasis, how a primary tumour locally invades and systemically disseminates using the phenotypic switching mechanism of epithelial to mesenchymal transition (EMT); however, much less is understood about how metastases are then formed. Breast cancer metastases often look (and may even function) as ‘normal’ breast tissue, a bizarre observation against the backdrop of the organ structure of the lung, liver, bone or brain. Mesenchymal to epithelial transition (MET), the opposite of EMT, has been proposed as a mechanism for establishment of the metastatic neoplasm, leading to questions such as: Can MET be clearly demonstrated in vivo? What factors cause this phenotypic switch within the cancer cell? Are these signals/factors derived from the metastatic site (soil) or expressed by the cancer cells themselves (seed)? How do the cancer cells then grow into a detectable secondary tumour and further disseminate? And finally—Can we design and develop therapies that may combat this dissemination switch? This review aims to address these important questions by evaluating long-standing paradigms and novel emerging concepts in the field of epithelial mesencyhmal plasticity.

Health benefits of n-3 polyunsaturated fatty acids: eicosapentaenoic acid and docosahexaenoic acid.

Abstract: Marine-based fish and fish oil are the most popular and well-known sources of n-3 polyunsaturated fatty acids (PUFAs), namely, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These n-3 PUFAs are known to have variety of health benefits against cardiovascular diseases (CVDs) including well-established hypotriglyceridemic and anti-inflammatory effects. Also, various studies indicate promising antihypertensive, anticancer, antioxidant, antidepression, antiaging, and antiarthritis effects. Moreover, recent studies also indicate anti-inflammatory and insulin-sensitizing effects of these fatty acids in metabolic disorders. Classically, n-3 PUFAs mediate some of these effects by antagonizing n-6 PUFA (arachidonic acid)-induced proinflammatory prostaglandin E₂ (PGE₂) formation. Another well-known mechanism by which n-3 PUFAs impart their anti-inflammatory effects is via reduction of nuclear factor-κB activation. This transcription factor is a potent inducer of proinflammatory cytokine production, including interleukin 6 and tumor necrosis factor-α, both of which are decreased by EPA and DHA. Other evidence also demonstrates that n-3 PUFAs repress lipogenesis and increase resolvins and protectin generation, ultimately leading to reduced inflammation. Finally, beneficial effects of EPA and DHA in insulin resistance include their ability to increase secretion of adiponectin, an anti-inflammatory adipokine. In summary, n-3 PUFAs have multiple health benefits mediated at least in part by their anti-inflammatory actions; thus their consumption, especially from dietary sources, should be encouraged.

Business Training and Female Enterprise Start-Up, Growth, and Dynamics: Experimental Evidence from Sri Lanka

Abstract: We conduct a randomized experiment in Sri Lanka to measure the impact of the most commonly used business training course in developing countries, the Start-and-Improve Your Business (SIYB) program. In contrast to existing business training evaluations which are restricted to microfinance clients, we consider two more representative groups: a random sample of women operating subsistence enterprises, and a random sample of women who are out of the labor force but interested in starting a business. Both samples are randomized into three groups: a control group, a group invited to attend training, and a group invited to receive training and who receive a cash grant conditional on completing training. We track impacts over four rounds of follow-up surveys taken over two years and find that the short- and medium-term impacts differ. For women already in business, we find that although training alone leads to some changes in business practices, it has no impact on business profits, sales or capital stock. In contrast the combination of training and a grant leads to large and significant improvements in business profitability in the first eight months, but this impact dissipates in the second year. For women interested in starting enterprises, we find that business training speeds up the process of opening a business, and changes the selection of who operates a business by making the entrants less analytically skilled, but leads to no increase in net business ownership by our final survey round. Receiving a grant results in poorer women opening businesses, but again does not increase net business ownership. Training appears to have increased the profitability and business practices of the businesses started up, suggesting it may be more effective for new owners than for enhancing existing businesses.

The renin-angiotensin system: a link between obesity, inflammation and insulin resistance

Abstract: Summary The renin-angiotensin system (RAS) is classically known for its role in regulation of blood pressure, fluid and electrolyte balance. Recently, several local RASs in organs such as brain, heart, pancreas and adipose tissue have also been identified. Evidence from clinical trials suggests that in addition to anti-hypertensive effects, pharmacological inhibition of RAS also provides protection against the development of type-2 diabetes. Moreover, animal models with targeted inactivation of RAS genes exhibit improved insulin sensitivity and are protected from high-fat diet-induced obesity and insulin resistance. Because there is evidence for RAS overactivation in obesity, it is possible that RAS is a link between obesity and insulin resistance. This review summarizes the evidence and mechanistic insights on the associations between RAS, obesity and insulin resistance, with special emphasis on the role of adipose tissue RAS in the pathogenesis of metabolic derangements in obesity.

Medicinal mushrooms in prevention and control of diabetes mellitus

Abstract: Diabetes mellitus is a life-threatening chronic metabolic disease caused by lack of insulin and/or insulin dysfunction, characterized by high levels of glucose in the blood (hyperglycemia). Millions worldwide suffer from diabetes and its complications. Significantly, it has been recognized that type 2 diabetes is an important preventable disease and can be avoided or delayed by lifestyle intervention. Presently, there are many chemical and biochemical hypoglycemic agents (synthetic drugs), that are used in treating diabetes and are effective in controlling hyperglycemia. However, as they may have harmful side-effects and fail to significantly alter the course of diabetic complications, natural anti-diabetic drugs from medicinal plants have attracted a great deal of attention. Medicinal mushrooms have been valued as a traditional source of natural bioactive compounds over many centuries and have been targeted as potential hypoglycemic and anti-diabetic agents. Bioactive metabolites including polysaccharides, proteins, dietary fibres, and many other biomolecules isolated from medicinal mushrooms and their cultured mycelia have been shown to be successful in diabetes treatment as biological anti-hyperglycemic agents. In this review we discuss the biological nature of diabetes and, in particular, explore some promising mushrooms that have experimental anti-diabetic properties, preventing or reducing the development of diabetes mellitus. The importance of medicinal mushrooms as agents of medical nutrition therapy and how their metabolites can be used as supportive candidates for prevention and control of diabetes is explored. Future prospects for this field of study and the difficulties and constraints that might affect the development of rational drug products from medicinal mushrooms are discussed.

Medicinal mushrooms in supportive cancer therapies: an approach to anti-cancer effects and putative mechanisms of action

Abstract: Medicinal mushrooms have been valued as natural sources of bioactive compounds since times immemorial and have been recognized as potential immunomodulating and anti-cancer agents. Their consumption has consistently been shown to have beneficial effects on human health. Cancer is a generic term for several types of diseases that can be chronic and are responsible for a large number of deaths worldwide. Although there has been considerable progress in modern cancer therapy research, difficulties in understanding the molecular behavior of various types of cancers and the numerous side effects experienced by patients from treatments means that this whole subject area is still problematic. Thus, biological immunotherapy using natural bioactive compounds as supportive treatments in conventional cancer therapies has become in vogue. Bioactive metabolites isolated from medicinal mushrooms have shown potential successes in cancer treatment as biological immunotherapeutic agents that stimulate the immune system against cancer cells. They also act as an effective source of anti-cancer agents, capable of interfering with cellular signal transduction pathways linked to cancer development and progression. In this review we compile available data on the characteristics of medicinal mushrooms that appear to be particularly effective as biological immunotherapeutic agents. Major consideration is given to biological constituents and the putative mechanisms of action by which bioactive compounds act on the human body. Consideration is also given to the benefits that have been claimed for the use of mushrooms in treating cancer and the future prospects of using medicinal mushrooms as potent supportive candidate bioagents for treatment of cancers is discussed.

One-Time Transfers of Cash or Capital Have Long-Lasting Effects on Microenterprises in Sri Lanka

Abstract: This brief summarizes the results of a gender impact evaluation study, entitled One-time transfers of cash or capital have long-lasting effects on microenterprises in Sri Lanka, conducted during the time period between 2005 to 2007 in Sri Lanka. The study observed that found long lasting impacts from one-time grants given in a randomized experiment to subsistence firms. Two main patterns emerged from this follow up study: the male treated group always had higher profits than the control group, and the gap did not shrink over time; and females in the control have similar profits to females in the treatment group. For females, much of the treatment gets diverted from the business to the household. Also, women are more likely to work in industries with low economies of scale. Funding for the study derived from Gender Action Plan, NSF Grant.

Tubulointerstitial damage as the major pathological lesion in endemic chronic kidney disease among farmers in North Central Province of Sri Lanka

Abstract: Chronic kidney disease of uncertain etiology (CKDu) in North Central Province of Sri Lanka has become a key public health concern in the agricultural sector due to the dramatic rise in its prevalence and mortality among young farmers. Although cadmium has been suspected as a causative pathogen, there have been controversies. To date, the pathological characteristics of the disease have not been reported. Histopathological observations of 64 renal biopsies obtained at Anuradhapura General Hospital from October 2008 to July 2009 were scored according to Banff 97 Working Classification of Renal Allograft pathology. The correlations between the histological observations and clinical parameters were statistically analyzed. Interstitial fibrosis and tubular atrophy with or without nonspecific interstitial mononuclear cell infiltration was the dominant histopathological observation. Glomerular sclerosis, glomerular collapse, and features of vascular pathology such as fibrous intimal thickening and arteriolar hyalinosis were also common. Although hypertension was identified as one of the common clinical features among the cases, it did not influence the histopathological lesions in all the cases. This study concludes that tubulointerstitial damage is the major pathological lesion in CKDu. Exposure(s) to an environmental pathogen(s) should be systematically investigated to elucidate such tubulointerstitial damage in CKDu.

A cross-cultural comparison of student learning patterns in higher education

Abstract: The aim of this study was to compare student learning patterns in higher education across different cultures. A meta-analysis was performed on three large-scale studies that had used the same research instrument: the Inventory of learning Styles (ILS). The studies were conducted in the two Asian countries Sri Lanka and Indonesia and the European country The Netherlands. Students reported use of learning strategies, metacognitive strategies, conceptions of learning and learning orientations were compared in two ways: by analyses of variance of students’ mean scale scores on ILS scales, as well as by comparing the factor structures of the ILS-scales between the three studies. Results showed most differences in student learning patterns between Asian and European students. However, many differences were identified between students from the two Asian countries as well. The Asian learner turned out to be a myth. Moreover, Sri Lankan students made the least use of memorising strategies of all groups. That Asian learners would have a propensity for rote learning turned out to be a myth as well. Some patterns of learning turned out to be universal and occurred in all groups, other patterns were found only among the Asian or the European students. The findings are discussed in terms of learning environment and culture as explanatory factors. Practical implications for student mobility in an international context are derived.

Clinical and histopathologic parameters in survival of oral squamous cell carcinoma

Abstract: Objective The aim of this study was to assess the relevance of clinical and histopathologic parameters on survival of oral squamous cell carcinoma (OSCC) patients in Sri Lanka. Study Design A cohort of 193 previously diagnosed OSCC patients were followed for up to 5 years. Clinical and histopathologic parameters were analyzed regarding local recurrence and 5-year survival after treatment. Results Site, stage, local recurrence, degree of differentiation, degree of keratinization, pattern of invasion, and status of the excision margins showed a significant association with the 5-year survival ( P P Conclusions Stage, pattern of invasion, and status of the excision margins are superior prognostic indicators of OSCC compared with other parameters.

TiO2 Surface Treatment Effects by Mg2+, Ba2+, and Al3+ on Sb2S3 Extremely Thin Absorber Solar Cells

Abstract: Sb2S3-based extremely thin absorber (ETA) solar cells of structure, , was fabricated with porous TiO2 surface treating by Mg2+, Ba2+, and Al3+ to be full-inorganic printed solar cells. The fabrication parameters of the ETA structure were optimized and the photovoltaic characteristics were improved significantly when double treatment in Mg2+ and Ba2+ were introduced. Best cells obtained using double treatment in Mg2+ and Ba2+ attained a short-circuit photocurrent of 13.4 mA/cm2, a open-circuit voltage of 0.584 V, a fill factor of 0.525, and a conversion efficiency 4.10% at 1 sun irradiation.

Efficiency enhancement by mixed cation effect in dye-sensitized solar cells with PAN based gel polymer electrolyte

Abstract: Dye-sensitized solar cells based on nano-porous TiO2 photo-anode and quasi-solid polymer (or gel) electrolytes are emerging as low cost alternatives to conventional inorganic photovoltaic devices. Although many attempts have been made in order to improve the relatively low power conversion efficiencies of these solar cells, to our knowledge there are very few reports aimed at using a binary system of two different iodide salts toward efficiency enhancement in these cells. In this paper we report for the first time in detail, the effect of using a binary iodide salt mixture with different size cations on the efficiency enhancement in dye sensitized solar cells with polyacrylonitrile (PAN) based gel polymer electrolyte and suggest a possible mechanism for this enhancement, based on short circuit photocurrent which is directly related to the iodide ion concentration [I-]. The gel electrolyte was made of PAN, ethelene carbonate (EC), Propylene carbonate (PC), salt mixture and I-2. The binary iodide salt mixture consists of potassium iodide (KI) and Tetra propyl ammonium iodide (Pr4NI). Although the gel electrolyte with 100% (w/w) KI exhibited the highest overall ionic conductivity at room temperature, it showed the lowest iodide ion (I-) contribution to conductivity. On the other hand, the electrolyte with 100% (w/w) Pr4NI exhibited the lowest overall ionic conductivity but had the highest iodide ion(I-) contribution. The dye-sensitized solar cells of configuration Glass/FTO/TiO2/N-719 Dye/electrolyte/Pt/FTO/glass were fabricated using the gel electrolytes of different salt ratios and with nanoporous TiO2 electrode sensitized with Ruthenium dye (N719). With identical electrolyte compositions, the solar cell with 100% (w/w) KI showed an efficiency of 4.98% and the cell with 100% (w/w) Pr4NI showed an efficiency of 4.47%. However, the cell with the mixed iodide system, 16.6% (w/w) KI + 83.4%(w/w) Pr4NI showed the highest efficiency of 5.36% with maximum short circuit current density (J(SC)) of 13.79 mA cm(-2), open circuit voltage (V-OC) of 679.10 mV and a fill factor of 57.25%. The variation of efficiency (eta) with iodide ion concentration [I-] follows the same trend as the J(SC) which appears to be governed by the iodide ion conductivity of the gel electrolyte. The dependence of the short circuit photocurrent and the open circuit photovoltage on the cation type generally agrees with reported data for related systems. However, the occurrence of a maximum in the solar cell efficiency and short circuit photocurrent at 16.6% (w/w)10 + 83.4% (w/w) Pr4NI salt composition is an important finding. The efficiency enhancement of about 8% achieved by employing the binary iodide mixture in the gel electrolyte instead of a single iodide salt, could be utilized for achieving efficiency enhancement in many dye sensitized solar cell systems based on polymeric, gel or solvent electrolytes.

Testing the independent species’ arrangement assertion made by theories of stochastic geometry of biodiversity

Abstract: The assertion that the spatial location of different species is independent of each other is fundamental in major ecological theories such as neutral theory that describes a stochastic geometry of biodiversity. However, this assertion has rarely been tested. Here we use techniques of spatial point pattern analysis to conduct a comprehensive test of the independence assertion by analysing data from three large forest plots with different species richness: a species-rich tropical forest at Barro Colorado Island (Panama), a tropical forest in Sinharaja (Sri Lanka), and a temperate forest in Changbaishan (China). We hypothesize that stochastic dilution effects owing to increasing species richness overpower signals of species associations, thereby yielding approximate species independence. Indeed, the proportion of species pairs showing: (i) no significant interspecific association increased with species richness, (ii) segregation decreased with species richness, and (iii) small-scale interspecific interaction decreased with species richness. This suggests that independence may indeed be a good approximation in the limit of very species-rich communities. Our findings are a step towards a better understanding of factors governing species-rich communities and we propose a hypothesis to explain why species placement in species-rich communities approximates independence.

Evidence of tubular damage in the very early stage of chronic kidney disease of uncertain etiology in the North Central Province of Sri Lanka: a cross-sectional study

Abstract: Background In the North Central Province of Sri Lanka, chronic kidney disease of uncertain etiology (CKDue) has increased markedly over the past 15–20 years.

Spatial distribution of fluoride in groundwater of Sri Lanka

Abstract: Fluoride ions in drinking water is well known for both beneficial and detrimental effects on health. Millions of inhabitants in the Dry Zone of Sri Lanka are vulnerable to fluorosis due to consumption of high fluoride groundwater. The objective of this study is to upgrade the spatial distribution map of groundwater fluoride levels in Sri Lanka. The map was prepared using nearly 14000 groundwater fluoride data that were collected from primary and secondary sources. The fluoride map of Sri Lanka indicates that the climate and hydrological conditions appear to play a major role in the geochemical distribution of fluoride in groundwater. In some cases, over 25 % of wells have more than 2 mg/L of fluoride, which is much higher than the recommended level for tropical countries. As shown in the map, even within the Dry Zone region, some low fluoride regions can be observed. This may probably be due to the effect of surface water, which contains fairly low levels of fluoride. In general, from among the chemical parameters in groundwater, fluoride stands out as an ion that appears to seriously affect the water quality of the Dry Zone. Doi: http://dx.doi.org/10.4038/jnsfsr.v40i4.5044 J.Natn.Sci.Foundation Sri Lanka 2012 40 (4):303-309

Diversity and Relationships of Eggplants from Three Geographically Distant Secondary Centers of Diversity

Abstract: Eggplant (Solanum melongena L.) was domesticated in the Indo-Birmanian region, which is also the primary center of diversity for this crop. From there eggplant spread to other regions, and diversity accumulated in several secondary centers of diversity. We have assessed the diversity and relationships of 52 accessions of eggplant from three geographically distant secondary centers of diversity (China, Spain, and Sri Lanka) using 28 morphological descriptors and 12 highly polymorphic genomic SSRs. A wide variation was found for most morphological traits, and significant differences among the three centers of diversity were detected for 22 of these traits. The PCA analysis showed that eggplants from the three origins were morphologically differentiated, and accessions from each of the three secondary centers of diversity presented a typical combination of morphological characteristics. In this respect, discriminant analysis showed that accessions could be correctly classified to their origin using only six traits. The SSR characterization identified 110 alleles and allowed obtaining a unique genetic fingerprint for each accession. Many alleles were found to be private to each origin, but no universal alleles were found for any of the origins. The PCA analysis showed that the genetic differentiation among origins was less clear than for morphological traits, although the analysis of the population structure shows that accessions mostly group according to the origin, but also provides evidence of migration among the three secondary centers of diversity. The genetic diversity (HT) within each origin was high, ranging between HT = 0.5400 (Sri Lanka) and HT = 0.4943 (China), while the standardized genetic differentiation (G’ST) among origins was moderate (G’ST = 0.2657). The correlation between morphological and SSR distances was non-significant (r = 0.044), indicating that both data are complementary for the conservation of germplasm and breeding of eggplant. These results are relevant for the management of genetic resources, breeding programmes, and evolutionary studies of eggplant.

Application of Coal Fly Ash in Agriculture: A Strategic Perspective

Abstract: Fly ash is a major waste of coal-power generation and its management is a major environmental and economic challenge, and it will become even more critical with a projected increase in the reliance on coal for power generation. The authors discuss how the unique physicochemical properties of ash can be strategically employed to ameliorate acidity and sodicity, and physical and fertility constraints, in agricultural soils. They show that with careful selection of ash type and methods and rates of application, mutually compatible with the soil and crop type, the often reported phytotoxicity due to high concentrations of certain trace metals can be avoided while maintaining the quality of produce and minimizing risk to the environment. Specific examples are presented to demonstrate where it is economical to use fly ash as a low-cost alternative to certain fertilizers and liming materials on farms. The authors also propose criteria for the selection of ash and for regulatory parameters that would ensure the s...

Efficiency enhancement in dye sensitized solar cells using gel polymer electrolytes based on a tetrahexylammonium iodide and MgI2 binary iodide system.

Abstract: Quasi-solid-state dye-sensitized solar cells have drawn the attention of scientists and technologists as a potential candidate to supplement future energy needs. The conduction of iodide ions in quasi-solid-state polymer electrolytes and the performance of dye sensitized solar cells containing such electrolytes can be enhanced by incorporating iodides having appropriate cations. Gel-type electrolytes, based on PAN host polymers and mixture of salts tetrahexylammonium iodide (Hex4N+I−) and MgI2, were prepared by incorporating ethylene carbonate and propylene carbonate as plasticizers. The salt composition in the binary mixture was varied in order to optimize the performance of solar cells. The electrolyte containing 120% Hex4N+I− with respect to weight of PAN and without MgI2 showed the highest conductivity out of the compositions studied, 2.5 × 10−3 S cm−1 at 25 °C, and a glass transition at −102.4 °C. However, the electrolyte containing 100% Hex4N+I− and 20% MgI2 showed the best solar cell performance highlighting the influence of the cation on the performance of the cell. The predominantly ionic behaviour of the electrolytes was established from the dc polarization data and all the electrolytes exhibit iodide ion transport. Seven different solar cells were fabricated employing different electrolyte compositions. The best cell using the electrolyte with 100% Hex4N+I− and 20% MgI2 with respect to PAN weight showed 3.5% energy conversion efficiency and 8.6 mA cm−2 short circuit current density.

Cyanobacteria: Pioneers of Planet Earth

Abstract: Cyanobacteria are among the earliest of inhabitants of Planet Earth and their existence can be traced back to 3.8 billion years. Their oxygenic photosynthesis led to the gradual conversion of the Earth‟s atmosphere from an anaerobic to an aerobic one. This change enabled the advent of aerobic organisms that eventually underwent rapid evolution and became the dominant, highly diverse members of the current global biodiversity. Cyanobacteria are ubiquitous in their distribution and are found in all the latitudes from Arctic and Anatarctic regions to the Tropical deserts perhaps reflecting their pioneering habitation of the primitive earth. They are also unique in their ability to simultaneously perform oxygenic photosynthesis and oxygen labile nitrogen fixation. Through these processes they make significant contributions to the Carbon and Nitrogen bio-geochemical cycles, particularly in the deep oceans. The ability of these organisms to fix N 2 either independently or in symbiosis with other organisms not only contributes to natural ecosystems but is applied in certain countries particularly for rice cultivation. Their ability to grow in highly polluted environments is also used in the treatment of sewage and industrial effluents. Cyanobacteria are the most efficient among all living organisms in the harvesting of solar energy and are currently looked at as highly attractive candidates for biofuel production. A few species are being used for the production of highly nutritive food supplements. On the negative side, some cyanobacteria form massive growths called „blooms‟ in water bodies and many of them produce toxins harmful to fish, digastric animals and are suspected to be responsible for certain human ailments. Having reviewed most of these aspects of cyanobacteria, it is concluded that knowledge on these little known organisms would be invaluable not only for students, scientists and environmentalists but also for industrialists and policy makers. Key words: cyanobacteria; blue-green algae; algal toxins; biofertilizers; biofuels DOI: http://dx.doi.org/10.4038/cjsbs.v40i2.3925 CJSBS 2011; 40(2): 71-88

Changing epidemiologic patterns of deliberate self poisoning in a rural district of Sri Lanka

Abstract: Acute poisoning is a major public health issue in many parts of the world. The epidemiology and the mortality rate is higher in low and middle income countries, including Sri Lanka. The aim of this study was to provide details about the epidemiology of acute poisoning in a rural Sri Lankan district and to identify the changing patterns and epidemiology of poisoning. A prospective study was conducted from September 2008 to January 2010 in all hospitals with inpatient facilities in Anuradhapura district of North Central Province of Sri Lanka. Acute poisoning data was extracted from patient charts. Selected data were compared to the data collected from a 2005 study in 28 hospitals. There were 3813 poisoned patients admitted to the hospitals in the Anuradhapura district over 17 months. The annual population incidence was 447 poisoning cases per 100,000 population. The total number of male and female patients was approximately similar, but the age distribution differed by gender. There was a very high incidence of poisoning in females aged 15–19, with an estimated cumulative incidence of 6% over these five years. Although, pesticides are still the most common type of poison, medicinal drug poisonings are now 21% of the total and have increased 1.6 fold since 2005. Acute poisoning remains a major public health problem in rural Sri Lanka and pesticide poisoning remains the most important poison. However, cases of medicinal drug poisoning have recently dramatically increased. Youth in these rural communities remain very vulnerable to acute poisoning and the problem is so common that school-based primary prevention programs may be worthwhile. Lalith Senarathna, Shaluka F Jayamanna, Patrick J Kelly, Nick A Buckley,michael J Dibley, Andrew H Dawson. These authors contributed equally to this work.

Tropical Application of Floating Treatment Wetlands

Abstract: The treatment efficiencies of floating treatment wetlands (FTWs) containing two types of macrophytes, Typha angustifolia and Canna iridiflora, were investigated in a pilot scale study in the tropical climate of Sri Lanka. In batch experiments, over 80 % of biological oxygen demand (BOD5) and ammonium (NH 4 + -N) removal was observed, while nitrate (NO 3 − -N) removal was over 40 %. Typha angustifolia showed slightly higher BOD5, NH 4 + -N and NO 3 − -N removal than Canna iridiflora. Because of higher and steady root growth, Typha angustifolia resulted in a better performance and has a greater potential to extract nutrients from wastewater and allow water-plant interactions than Canna iridiflora whose root mat is thick and compact. Similar to the batch system, the continuous flow systems performed better at most times with Typha angustifolia. FTWs with Typha angustifolia may be considered a possible solution for lake restoration where there are space and cost constraints.