The University of Peradeniya is a state university in Sri Lanka, funded by the University Grants Commission. It was established as the University of Ceylon in 1942.The University of Peradeniya hosts eight faculties , two postgraduate institutes, 10 centres, 73 departments, and teaches about 11,000 students in the fields of Medicine, Agriculture, Arts, Science, Engineering, Dental science, Veterinary Medicine and Animal Science and Allied Health Science. It claims to the largest government endowment by a higher educational institution in Sri Lanka, based on its large staff and faculties/departments. Wikipedia.
Bandaranayake P.C.G.,University of Peradeniya |
Yoder J.I.,University of California at Davis
Molecular Plant-Microbe Interactions | Year: 2013
Parasitic species of the family Orobanchaceae are devastating agricultural pests in many parts of the world. The control of weedy Orobanchaceae spp. is challenging, particularly due to the highly coordinated life cycles of the parasite and host plants. Although host genetic resistance often provides the foundation of plant pathogen management, few genes that confer resistance to root parasites have been identified and incorporated into crop species. Members of the family Orobanchaceae acquire water, nutrients, macromolecules, and oligonucleotides from host plants through haustoria that connect parasite and host plant roots. We are evaluating a resistance strategy based on using interfering RNA (RNAi) that is made in the host but inhibitory in the parasite as a parasite-derived oligonucleotide toxin. Sequences from the cytosolic acetyl-CoA carboxylase (ACCase) gene from Triphysaria versicolor were cloned in hairpin conformation and introduced into Medicago truncatula roots by Agrobacterium rhizogenes transformation. Transgenic roots were recovered for four of five ACCase constructions and infected with T. versicolor against parasitic weeds. In all cases, Triphysaria root viability was reduced up to 80% when parasitizing a host root bearing the hairpin ACCase. Triphysaria root growth was recovered by exogenous application of malonate. Reversetranscriptase polymerase chain reaction (RT-PCR) showed that ACCase transcript levels were dramatically decreased in Triphysaria spp. parasitizing transgenic Medicago roots. Northern blot analysis identified a 21-nucleotide, ACCasespecific RNA in transgenic M. truncatula and in T. versicolor attached to them. One hairpin ACCase construction was lethal to Medicago spp. unless grown in media supplemented with malonate. Quantitative RT-PCR showed that the Medicago ACCase was inhibited by the Triphysaria ACCase RNAi. This work shows that ACCase is an effective target for inactivation in parasitic plants by trans-specific gene silencing. © 2013 The American Phytopathological Society.
Wijetunge J.J.,University of Peradeniya
Continental Shelf Research | Year: 2014
This paper describes a multi-scenario, deterministic analysis carried out as a pilot study to evaluate the tsunami hazard and risk distribution in the southwest coast of Sri Lanka. The hazard and risk assessment procedure adopted was also assessed against available field records of the impact of the Indian Ocean tsunami in 2004. An evaluation of numerically simulated nearshore tsunami amplitudes corresponding to 'maximum-credible' scenarios from different subduction segments in the Indian Ocean surrounding Sri Lanka suggests that a seismic event similar to that generated the tsunami in 2004 can still be considered as the 'worst-case' scenario for the southwest coast. Furthermore, it appears that formation of edge waves trapped by the primary waves diffracting around the southwest significantly influences the nearshore tsunami wave field and is largely responsible for relatively higher tsunami amplitudes in certain stretches of the coastline under study. The extent of inundation from numerical simulations corresponding to the worst-case scenario shows good overall agreement with the points of maximum penetration of inundation from field measurements in the aftermath of the 2004 tsunami. It can also be seen that the inundation distribution is strongly influenced by onshore topography. The present study indicates that the mean depth of inundation could be utilised as a primary parameter to quantify the spatial distribution of the tsunami hazard. The spatial distribution of the risk of the tsunami hazard to the population and residential buildings computed by employing the standard risk formula shows satisfactory correlation with published statistics of the affected population and the damage to residential property during the tsunami in 2004. © 2013 Elsevier Ltd.
Ileperuma O.A.,University of Peradeniya
Materials Technology | Year: 2013
Dye sensitised solar cells (DSCs) based on mesoporous nanostructured TiO 2 have attracted attention as an alternative to silicon photovoltaics. However, the use of a liquid electrolyte causes practical problems of leakages and its volatilisation, desorption and photodegradation of the dye, corrosion of the platinum secondary electrode and ineffective sealing of cells for long term applications in solar panels. Some of the attempts to solve this problem include the use of polymer electrolytes, gelling agents and both organic and inorganic hole conductors. A common feature of all such alternatives is the notable reduction in efficiency of the resultant solar cells primarily, due to the lower mobility of the iodide species through the solid or quasi-solid medium and imperfect wetting of pores with the electrolyte. The conversion efficiencies with the gel polymer electrolytes typically do not exceed 5%, but even at low efficiencies, these cells may become viable alternatives to the organic liquid containing Gratzel type cells due to improved stability and better sealing ability. The dyes are less liable to undergo photocorrosion and desorption, and the corrosion effects on the Pt electrode are lower. Some commonly used polymer electrolytes include poly(ethylene oxide), poly(propylene oxide), poly(acrylonitrile), poly(methyl methacrylate), poly(vinyl chloride) and poly(vinylidene fluoride). Plasticisers employed are ethylene carbonate, propylene carbonate, dimethyl carbonate, c-butyl lactone and diethylene carbonate. In addition, inert fillers, such as TiO 2, SiO 2, etc., are added to enhance ionic conductivity and stability at the interface with electrodes. These self-sealing gel polymer electrolytes have reported efficiencies of about 2-5%. Recently, the poly(acrylonitrile) based gel polymer electrolytes are reported to give an efficiency of 7.5% for the TiO 2/Ru-N719 system under AM 1.5 illumination. Incorporation of TiO 2 nanoparticles increases the efficiency of a DSC employing poly(vinylidene fluoride-cohexafluoropropylene) from 5.72 to 7.18% where the standard liquid electrolyte gave an efficiency of 7.01%. The nanoparticles here are assumed to reduce recombination at the interface of dyed electrode/electrolyte. This review will cover only the application of gel polymer electrolytes for dye sensitised TiO 2 systems in quasi-solid state solar cells and will not cover the closely related areas of gelated electrolytes where the standard liquid electrolyte is gelated with gelling agents and conducting polymers used as hole conductors. © 2013 W. S. Maney &Son Ltd.
Perera B.M.A.O.,University of Peradeniya
Animal Reproduction Science | Year: 2011
The domestic water buffalo (Bubalus bubalis) has an important role in the agricultural economy of many developing countries in Asia, providing milk, meat and draught power. It is also used in some Mediterranean and Latin American countries as a source of milk and meat for specialized markets. Although the buffalo can adapt to harsh environments and live poor quality forage, reproductive efficiency is often compromised by such conditions, resulting in late sexual maturity, long postpartum anoestrus, poor expression of oestrus, poor conception rates and long calving intervals. The age at puberty is influenced by genotype, nutrition, management and climate, and under favourable conditions occurs at 15-18 months in river buffalo and 21-24 months in swamp buffalo. The ovaries are smaller than in cattle and contain fewer primordial follicles. Buffalo are capable of breeding throughout the year, but in many countries a seasonal pattern of ovarian activity occurs. This is attributed in tropical regions to changes in rainfall resulting in feed availability or to temperature stress resulting in elevated prolactin secretion, and in temperate regions to changes in photoperiod and melatonin secretion. The mean length of the oestrous cycle is 21 days, with greater variation than observed in cattle. The signs of oestrus in buffalo are less overt than in cattle and homosexual behaviour between females is rare. The duration of oestrus is 5-27 h, with ovulation occurring 24-48 h (mean 34 h) after the onset of oestrus. The hormonal changes occurring in peripheral circulation are similar to those observed in cattle, but the peak concentrations of progesterone and oestradiol-17β are less. The number of follicular waves during an oestrous cycle varies from one to three and influences the length of the luteal phase as well as the inter-ovulatory interval. Under optimal conditions, dairy types managed with limited or no suckling resume oestrus cyclicity by 30-60 days after calving, while swamp types with free suckling do so at 60-90 days. However, in many farming systems prolonged postpartum anoestrus is a major problem, and the causes include poor nutrition and body condition, and stress due to harsh climates and improper management. Synchronization of time or induction of oestrus can be done using the same regimens as applied in cattle, using various combinations of prostaglandins, progesterone releasing devices, GnRH and eCG, but success rate is poor when treatment is done during the periods of marginal breeding activity or seasonal anoestrus. © 2010 Elsevier B.V.
Kalupahana N.S.,University of Tennessee at Knoxville |
Kalupahana N.S.,University of Peradeniya |
Moustaid-Moussa N.,University of Tennessee at Knoxville
Obesity Reviews | Year: 2012
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. © 2011 The Authors. obesity reviews © 2011 International Association for the Study of Obesity.
Jayasekara J.M.,University of Peradeniya
The Ceylon medical journal | Year: 2013
In early nineties investigators noticed an alarmingly high incidence of an apparently new form of chronic kidney disease of unknown aetiology (CKD-U) in some parts of Sri Lanka. The aim of the study was to investigate the geographical distribution of CKD-U using GIS and GPS mapping. Community based information was collected from 11,630 patients for GIS mapping using ARC 9.2 software. Based on GIS mapping, two locations were selected for GPS mapping to locate the households of 863 CKD-U patients with reference to reservoirs, irrigation canals and the topography of the areas. GIS mapping indicated five high prevalence areas of CKD-U. Communities who consumed water from natural springs showed a low prevalence of the disease. GPS mapping showed that most of the affected villages were located below the reservoirs and canals with stagnant irrigated water. Epidemiological data on geographical distribution infers that while older foci of CKD-U are persisting, there is an emergence of new foci with time. The location of the affected villages below the level of the reservoirs/canals may indicate the possibility of draining of irrigated water to the shallow wells of the households, which is the source of drinking water.
News Article | March 25, 2016
While wildlife enriches daily life, strengthens ecosystems and attracts visitors, it can also damage crops and carry disease. Densely populated and rapidly changing places such as Sri Lanka – where human settlements, domestic animals and wildlife mingle closely – need effective ways to manage these benefits and risks. Recent epidemics have shown the critical role that wildlife health monitoring can play. But like many low- and middle-income countries, Sri Lanka lacks the needed infrastructure and expertise. Since 2011, Sri Lanka has had its own national wildlife health centre, co-managed by three government agencies and the University of Peradeniya, and mentored by the Canadian Wildlife Health Cooperative. With support from Canada's International Development Research Centre, a four-year collaboration between the University of Peradeniya and the University of Saskatchewan now aims to build the expertise needed for a national program of research and surveillance to help detect and manage health issues linked to interactions between wildlife and humans. Research co-leader Dr Ted Leighton stresses the need to go beyond cataloguing wildlife and disease. "The human and social dimensions of managing health issues at the human-wildlife interface are severely neglected," he says. "Finding pathogens is relatively easy. The key is knowing how to communicate, educate and motivate risk-reducing behavioural change in human communities at risk." In a first phase of the research, the team identified six study sites where local communities live near protected areas. The sites represent a range of wildlife habitats and agro-ecological conditions. Researchers worked with villagers – including indigenous Adivasi or Vedda communities – to explore their beliefs, perceptions and contact with wild animals and to identify related conflicts or health risks. These explorations showed that, while some misconceptions exist, villagers are quite knowledgeable about the risks of transmittable diseases such as rabies, leptospirosis and Japanese encephalitis. Some villages raised concerns that merit further investigation, such as abnormal jackal behaviour and cases of anaemic sambar deer. The chief aim, however, is to build a critical mass of Sri Lankan scientists able to bridge animal and human health and development. According to Dr Oswin Perera, director of the Sri Lanka Wildlife Health Centre, "The project is making an important contribution to training, capacity building and networking among staff and students from the university and government agencies." Graduate students in veterinary and social sciences are taking part in the research and gaining expertise in areas such as veterinary pathology, epidemiology and community dynamics. Government officials and field staff from the wildlife, veterinary, human health and administrative sectors are helping to set project priorities, taking part in research and incorporating their new capacity in wildlife health into their programs. While building expertise in Sri Lanka, the joint effort is developing organisational models and training and evaluation tools for wildlife health research that may help other countries grappling with emerging diseases and increasing land use conflicts.
News Article | March 2, 2017
Fiberstar, Inc. (http://www.FiberstarIngredients.com), a global market leader in clean label food ingredient solutions for the food and beverage industry announced the winners to the Citri-Fi 125 Student Innovation Contest. Citri-Fi 125, a natural, non-GMO citrus fiber is one of the most recent additions to the Citri-Fi portfolio. To find new uses for this natural citrus fiber, Fiberstar launched a global innovation contest targeting University students. Over 25 applicants, globally, submitted a proposal in how to use the Citri-Fi 125. “This is the first time a program like this has been created, so we are pleased with the interest from the applicants,” says Fiberstar, Inc. President and CEO, John Haen. “We continue to support University food science programs by offering students opportunities to create food ingredient solutions for the real world.” A panel of judges ranked the students’ applications based on originality of concept, justification/market need, ingredient commercial feasibility, technical feasibility and quality of their report. A total of $25,000 was awarded amongst the six winning proposals. The following winning teams and applications are: 1st Place: Citrus Fiber as an Effective Fat Blocker in Fried Seafood: Oregon State University Seafood Research and Education Center, U.S. (Dr. Jae Park, Kaitlin Junes and Angela Hunt). Citri-Fi 125 used in a coating formulation to reduce oil pick-up not only provides potential cost savings to processors due to reduced oil usage, but this also provides manufacturers opportunities to reduce fat and calories. The study also showed yield improvement due to increased pick-up and reduced cooking losses. 2nd Place: Reduced Fat Instant Laksa Paste: Surya University, Indonesia (Sylviana, Meutia Wafa' Khairunnisa Hakim, Amelia Adinda and Bryan Raharja). Citri-Fi 125 is used to reduce the amount of coconut milk used in Laksa paste to provide potential cost savings and fat reduction. Citri-Fi 125 provides emulsification stabilization and improved mouthfeel to simulate the texture of the full-fat version. This may be applicable to other coconut milks pastes, spreads, beverages and soups found not only in Asia, but also in other parts of the world due to the growing use of coconut. 3rd Place: Citri-Crunch Healthy Savory Extruded Pork Snack: Washington State University, U.S. (Ryan Kowalski, Bon-Jae Gu, Maria Dian Pratiwi Masli, Siyuan Wang and Hongchao Zhang). Citri-Fi 125 helped reduce the oil uptake and improved the flavor by enhancing the umami flavor of monosodium glutamate when reducing the sodium. This not only aligns with the market’s need for healthier snacks, but also offers snack manufacturers cost savings opportunities in less oil usage. 4th Place: Chicken Sausage with Reduced Oil & Improved Sensory: University of Peradeniya, Sri Lanka (Miss A.M. Aruni Shanika, Dr. Himali Samaraweera, Nirupa Edirisinghe, Hashinee Medika Ariyasena and Nuwan Jayawardena). Citri-Fi 125 provided emulsification stabilization and texturizing to help reduce the oil by at least 30% while maintaining a full-fat mouthfeel. This provides cost savings and health benefits due to the fat/caloric reduction. 5th Place: Calcium Fortification to Increase Viscosity and Enhance Gelling Properties: University of Guelph, Canada (Lisa Indris). Incorporating calcium with Citri-Fi 125 in liquid food formats improves the viscosity and provides improved stabilization. This enhanced feature opens doors in the natural dairy category where stabilization and mouthfeel are desired and needed. 6th Place: Natural Color Stabilizer in Berry Yammee Topping: Cornell University, U.S. (Fiona Harnischfeger, Sofía Lara, Victoria Chen, Katrina Cariño, Ana Chang, Sierra Jamir and Shiyu Cai). Citri-Fi 125 stabilizes natural colors during shelf-life to prevent phase separation and color bleeding. This benefit is crucial for consumer acceptance when using vibrant natural colors to indicate freshness. Fiberstar also offers other citrus fiber solutions via 100 series line which contains different fiber content than the 125 series, the 200 series which is citrus fiber and guar gum and the 300 series which is the citrus fiber and xanthan gum. The Citri-Fi citrus fiber product lines provide food manufacturers clean label texturizing solutions for various food products including bakery, beverages, dressings, meats, sauces and dairy. “We are excited to enhance our formulating tool box by promoting Citri-Fi 125 citrus fiber. Our team will continue working closely with our Customers to provide superior technical service support, quality product and new ideas especially those generated from the most recent innovation contest. And we look forward to connecting with Universities and students in the future to continue the collaboration.” For more information about the Innovation Contest applications, please contact Dr. Brock Lundberg at (651) 271-0328
News Article | March 31, 2016
A team of scientists has come across a tadpole burrowing through sand in India's Western Ghats. The team of Gayani Senevirathne from the University of Peradeniya and his colleagues deemed the discovery a fascinating one, as tadpoles would not usually burrow through sand or swallow that material. The remarkable tadpoles - found deep in streambeds where they exist in complete darkness until fully developing into froglets — belong to the Micrixalidae or Indian Dancing frog family. The researchers genetically confirmed their identity as Micrixalus herrei. Study author and professor SD Biju of University of Delhi said that this is the first documentation of tadpoles in this frog family, as only adult dancing frogs had been seen over the last century. "These tadpoles probably remained unnoticed all these years because of their fossorial nature, which in itself is a rare occurrence in the amphibian world," he reveals. Indian dancing frogs are known to sit on boulders in streams while they wave their legs as a means of sexual and territorial display. The tadpoles of this family, however, had remained mysterious to scientists - in fact the only one among frogs and toads that maintained such mystery. But the biologists ventured to know these tiny creatures better. The tadpoles are characterized by skin-covered eyes for protection from abrasion while they burrow through gravel beds, as well as muscular eel-like bodies. Although they lack teeth, they retain well-serrated jaw sheaths, which help block large grains of sand from entering their mouths during feeding and movement. Their gut, too, contains small grains of sand and decaying organic stuff acting as nutrient sources. A double staining procedure that scrutinized the tadpoles' bones also showed they have ribs that provide increased muscle attachment to help them navigate through sand. "Lime sacs" or white globular sacs containing calcium carbonate are another feature of these tadpoles that are barely seen in other frogs. There had been very little known about the habitat requirements of the tadpoles. Current observations, though, revealed that they live in sandy banks under canopy-shielded streams. These findings confirm the unique amphibian showcase of the Western Ghats, which is considered a biodiversity hotspot and a good source of information for frog conservation. The findings were published March 30 in the journal PLOS ONE.
News Article | March 30, 2016
The group of scientists from University of Delhi, University of Peradeniya and Gettysburg College discovered and documented the interesting tadpole of the Indian Dancing frog family, Micrixalidae. These tadpoles were discovered from deep recesses of streambeds, where they live in total darkness until they fully develop into froglets. The identity of the tadpoles as Micrixalus herrei is genetically confirmed. These tadpoles are endowed with muscular eel-like bodies and skin-covered eyes, which facilitate burrowing through gravel beds. They lack teeth but have well-serrated jaw sheaths, which may help prevent large sand grains from entering the mouth while feeding and moving through sand. The tadpole gut contains small sand grains together with decaying organic matter, which acts as a nutrient source. The Indian Dancing frogs typically wave their legs as a territorial and sexual display while sitting on boulders in streams. Though these displays are well known, the tadpoles of these frogs were completely unknown. This was, in fact, the only family of frogs and toads for which the tadpoles remained a mystery. Prof. SD Biju from University of Delhi says, "We provide the first confirmed report of the tadpoles of Indian Dancing frog family. These tadpoles probably remained unnoticed all these years because of their fossorial nature, which in itself is a rare occurrence in the amphibian world." They examined the external morphology of the tadpoles and scrutinized their bones using a double staining procedure, which revealed the presence of ribs in very early stages of tadpoles. Prof. Madhava Meegaskumbura from University of Peradeniya states, "only four families of frogs are reported to have ribs, but we show that at least some of Micrixalidae also have ribs, even as tadpoles; this adaptation may provide for greater muscle attachment, helping them wriggle through sand." Also, whitish globular sacs storing calcium carbonate, known as "lime sacs," are present even in juvenile frogs of Micrixalus, which is uncommon in other frogs. Very little is known about the habitat requirements of these tadpoles. Observations made so far show that the tadpoles inhabit sandy banks under canopy-covered streams. The new finding reiterates the uniqueness of amphibians of the Western Ghats biodiversity hotspot, providing a platform for future studies on this amphibian family, while also delivering useful information for conservation of these ancient and endemic frogs. Explore further: Researchers discover unexpected patterns in evolution of frog life cycles More information: Senevirathne G, Garg S, Kerney R, Meegaskumbura M, Biju SD (2016) Unearthing the Fossorial Tadpoles of the Indian Dancing Frog Family Micrixalidae. PLoS ONE 11(3): e0151781. DOI: 10.1371/journal.pone.0151781