128 research outputs found

    Utilization of aquatic plants: a method to enhance the productivity of water in seasonal tanks in the Anuradhapura District

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    Heavy infestations of aquatic plants in a water body cause considerable economic and ecological losses. Many seasonal tanks in the Anuradhapura District suffer from this problem and cannot be neglected in water resource development and management schemes. This study was focused on the uses of aquatic plants and the problems caused by huge manifestations of aquatic plants in the selected seasonal tanks in the Anuradhapura District. The study was conducted in four seasonal tanks viz., Galkulama, Thirappane Maradankadawala and Thibbatuwewa in the Anuradhapura District. Information on the utilization of aquatic plants, exploitation level and harmful effects were gathered by using a structured questionnaire to interview people who were residing close to the study sites. The attitudes of the public towards the aquatic plants i.e., conservation of aquatic plants, the potential uses of native plants and harmful effects of invasive aquatic plants were collected. Twelve species were identified as economically important aquatic plants through the questionnaire survey. Among the 50 respondents, 92 % utilized aquatic plants for food, 58 % utilized flowers for offerings and decorations, 52 % utilized aquatic plants for medicinal purposes, 42 % utilized them as ornamental plants, 30 % used them as bio-fertilizers and 28 % utilized them for weaving. The edible aquatic plants consumed by the rural community in the Anuradhapura District are Ipomoea aquatica (72 %), Alternanthera sessilis (66 %), Nelumbo nucifera (64 %), Nymphaea pubescens (60 %) and Aponogeton spp. (52 %). Some edible aquatic plants, namely Neptunia oleracea, Ottelia alismoides and Ceratopteris thalictriodes, which are present in the Anuradhapura District, are not consumed, although these are consumed in many other countries. N. nucifera is the most commonly used flower for offerings in the temples and for decorations. In addition, N. pubescens, Nymphaea nouchali are also used for flowers. Bacopa monnieri, N. nucifera, Acanthus illicifolia, N. nouchali and Aponogeton spp. have been recorded as medicinally important plants. Though there are many ornamentally important aquatic plants, only N. pubescens, N. nouchali, B. monnieri, Nymphoides hydrophylla are used. Salvinia molesta and Eichhornia crassipes are the two aquatic plants commonly used as bio fertilizers. With reference to the questionnaire survey, there were seven major problems that were discovered to exist due to heavy infestations of aquatic weeds in the water bodies viz., sedimentation and unsuitability for domestic use, interference with navigation, effects on fisheries, blocking irrigation canals and evapotranspiration. The most problematic plants in the Anuradhapura District include E. crassipes, N. nucifera, S. molesta, Pistia stratiotes and Ceratophyllum demersum. Economically important aquatic plants available in the shallow water bodies of the Anuradhapura District, are marginally utilized, when compared with the utilization of aquatic plants in the global scenario. There appears to be a lack of a well organized action plan to cope with this situation. The public suffer a lot from the problems created by the heavy mass of aquatic plants, which covered the village tanks. The public are, however, willing to get organized and to engage in a participatory approach to restore their water bodies. There is a need for research and development of management strategies for the sustainable utilization of these valuable resources. Awareness programs should be conducted to promote sustainable utilization of aquatic plants. Creating awareness among the people about the nutritional and economic benefits of these natural resources will be useful for Sri Lanka, as a developing nation.Length: pp.23-32Aquatic plantsTanks

    Multi-Scaling of Correlation Functions in Single Species Reaction-Diffusion Systems

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    We derive the multi-fractal scaling of probability distributions of multi-particle configurations for the binary reaction-diffusion system A+AA+A \to \emptyset in d2d \leq 2 and for the ternary system 3A3A \to \emptyset in d=1d=1. For the binary reaction we find that the probability Pt(N,ΔV)P_{t}(N, \Delta V) of finding NN particles in a fixed volume element ΔV\Delta V at time tt decays in the limit of large time as (lntt)N(lnt)N(N1)2(\frac{\ln t}{t})^{N}(\ln t)^{-\frac{N(N-1)}{2}} for d=2d=2 and t^{-Nd/2}t^{-\frac{N(N-1)\epsilon}{4}+\mathcal{O}(\ep^2)} for d<2d<2. Here \ep=2-d. For the ternary reaction in one dimension we find that Pt(N,ΔV)(lntt)N/2(lnt)N(N1)(N2)6P_{t}(N,\Delta V) \sim (\frac{\ln t}{t})^{N/2}(\ln t)^{-\frac{N(N-1)(N-2)}{6}}. The principal tool of our study is the dynamical renormalization group. We compare predictions of \ep-expansions for Pt(N,ΔV)P_{t}(N,\Delta V) for binary reaction in one dimension against exact known results. We conclude that the \ep-corrections of order two and higher are absent in the above answer for Pt(N,ΔV)P_{t}(N, \Delta V) for N=1,2,3,4N=1,2,3,4. Furthermore we conjecture the absence of \ep^2-corrections for all values of NN.Comment: 10 pages, 6 figure

    CARBON SEQUESTERING THROUGH THE PHOTOSYNTHESIS IN RUBBER PLANTATIONS; A COMPARISON BETWEEN GENOTYPES

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    Being an industrial crop, rubber (Hevea brasilensis) is having a consistentdemand and grown in smallholdings under different environmental conditionsproviding an economically viable (in terms of both latex and timberproduction) and socially acceptable system. Also in terms of theenvironmental benefits, rubber helps to mitigate climate change through thefixing of atmospheric carbon and reducing the carbon emission formnonrenewable resources. Therefore, the present study aimed to assess thegenotypic differences in carbon fixing capability of field grown maturerubber cultivations with two specific objectives, 1) to quantify the potentialcarbon fixation of the mature rubber plantations through the CO2 assimilationand 2) to establish the genotypic differences of rubber in fixing atmosphericcarbon.The experiment was' conducted in the Dartonfield estate of the RubberResearch Institute at Agalawatte. Two promising genotypes i.e. RRIC 100and RRIC 121 at maximum productivity (i.e. in mature stage; 12 years old)were selected for the study. The assessment of the carbon fixation capabilityof rubber tree was based on measurements on leaf level photosynthesis, leafarea distribution and light attenuation of the rubber canopy. CO2 assimilationrates in rubber leaves under varying light levels were monitored with aportable infra red gas analyzer after dividing the canopy into three strata andthen, the parameters of light response curve of photosynthesis were estimatedusing a quadratic function. Leaf area distribution was assessed by physicalcounting with point quadrats and the available light for the photosynthesis indifferent canopy levels was estimated using existing ecophysiological modelsand then, canopy photosynthetic rates were calculated.In general, mature rubber was capable of sequestering 22 MT of carbon perhectare annually. Monthly values of carbon fixed differed according to thenumber of sunny and dull days. The highest rate of carbon sequestering wasgiven in the month of March, whilst November has shown the lowest rate.The value estimated for the whole economic lifecycle of rubber was 660MT/ha. The genotype, RRIC 121 was superior (160% greater) to RRIC 100 in fixing atmospheric carbon with annual rates of 31.8 and 12.2 MTha-1,respectively. Differences in the capacity of photosynthetic apparatus andcanopy architecture were identified as the reasons for the genotypicdifferences in carbon sequestering.

    Use of a rapid diagnostic test to detect cutaneous leishmaniasis in Sri Lanka

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    Objectives: This study was initiated to determine the sensitivity and specificity of a commercially available rapid diagnostic test (RDT) to detect leishmania antigen in cutaneous leishmaniasis(CL) skin lesions among Sri Lankan patients compared to PCR and Slit skin smear(SSS).Methods: Patients clinically suggestive of CL lesions were subjected to parasitological investigations. The clinical history was collected by the researcher. Samples were collected by a qualified trained medical officer from the suspected CL lesions at the dermatology clinic in the Hambantota hospital and from the patients coming to the Department of Parasitology, Faculty of Medical Sciences, University of Sri Jayewardenepura. RDT was done at the Hambantota hospital and samples were brought to the Department of Parasitology, to perform SSS, PCR and cultures.Results: Fifty samples have been collected thus far and PCR was performed only in 48 samples. Out of the 50 samples only 9 were positive by RDT and 32 by SSS and PCR. The 9 samples that were positive for RDT were positive by SSS and 7 positive by PCR. Of the 41 samples that were negative by RDT, 16 were negative by PCR as well as SSS.Conclusions: From the data collected it can concluded that RDT is not the best method to diagnose CL skin lesions in patients in Sri Lanka. Also it confirms that the best method to diagnose leishmaniasis is PCR

    Detection of Seismic Infrasonic Elephant Rumbles Using Spectrogram-Based Machine Learning

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    This paper presents an effective method of identifying elephant rumbles in infrasonic seismic signals. The design and implementation of electronic circuitry to amplify, filter, and digitize the seismic signals captured through geophones are presented. A collection of seismic infrasonic elephant rumbles was collected at a free-ranging area of an elephant orphanage in Sri Lanka. The seismic rumbles were converted to spectrograms, and several methods were used for spectral feature extraction. Using LasyPredict, the features extracted using different methods were fed into their corresponding machine-learning algorithms to train them for automatic seismic rumble identification. It was found that the Mel frequency cepstral coefficient (MFCC) together with the Ridge classifier machine learning algorithm produced the best performance in identifying seismic elephant rumbles. A novel method for denoising the spectrum that leads to enhanced accuracy in identifying seismic rumbles is also presented.Comment: 8 pages, 7 figures, journa

    Assessment on timber and carbon in rubber plantations with special reference to the wet zone of Sri Lanka

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    Rubber (Hevea brasilensiss has traditionally been cultivated for the latex extraction; however, itsimportance in other uses, particularly producing quality timber and sequestering atmospheric carbonas a permanent sink, is also often highlighted. The amount of timber produced and carbon sequesteredin rubber trees has been assessed in isolations. Those values would differ under different growthconditions and to date, no simple protocol is available to quantify the amount of timber and carbon inrubber plantations. Therefore, the study reported here was aimed to develop simple growth models toassess the timber production and carbon fixing capability of rubber plantations in Sri Lanka.Initially, a growth function was developed to assess the girth development with respect to age andthereafter another three functions to quantify the amount of timber, biomass and carbon in the rubbertree based on girth diameter. Also, wood density variation with age of the tree was modeled todetermine the biomass in timber under different age categories. The assessment on the availablecarbon was based on the carbon content in unit biomass and the total amount of biomass in the tree.Growth data required for the girth development function were gathered from secondary sources andgirth measurements made on existing rubber clearings. Destructive sampling was conducted to assessthe timber, biomass and wood density.Based on above models, an average rubber tree at 30 years achieves a girth of 88.64 ern and produces0.656 m' of timber and 594.46 kg of biomass. The amount of atmospheric carbon fixed in timber atthis age was estimated as 193.7 kg per tree and 45.86 MT per hectare. However, total amount oforganic carbon fixed in above ground components was 220.8 kg per tree and 52.27 MT per hectare.The models of this study were developed under general conditions in the wet zone, hence should bevalidated for drier regions of the country before any wide scale adoption.

    Role of natural killer T cells in the pathogenesis of dengue infections

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    Objectives: The dengue virus exploits cellular lipid metabolism pathways and natural killer T cells (iNKT), which recognize glycolipids have been suggested to play a role in mouse models of acute dengue. Therefore, we set out to determine if iNKT cells play a role in acute dengue infectionMethods: The frequency of iNKT cells (CD3+, Vα24+) was determined in 49 acute dengue and 22 healthy individuals. The functionality and phenotype of iNKT cell subsets were defined only in 19 patients and 10 controls by flow cytometry. Clinical disease severity was determined by the WHO 2011 guidelinesResults: The proportion of iNKTs in patients with acute dengue were significantly higher (P=0.03) compared to healthy individuals. We found that the CD4+ iNKTs, which produce inflammatory cytokines and are less cytotoxic, were significantly expanded (p=0.01) in acute dengue. iNKTs of patients were also significantly (p=0.02) more activated (both CD38+ and HLA-DR+), that iNKT cell activation significantly and positively correlated with dengue-specific IgG antibody titres (Spearmans’ r=0.5018, P=0.03). iNKT of patients were also predominantly of the immature phenotype, as the expression of CD161 was significantly more than in healthy individuals (p=0.01).Conclusions: As the iNKT cell population, especially of the CD4+ T cell subset appears to be highly activated and expanded in acute dengue, iNKT cells could be contributing to the pathogenesis of dengue infection

    Sustainability as corporate culture of a brand for superior performance

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    This is the post-print version of the final paper published in the Journal of World Business. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2012 Elsevier B.V.Sustainability research highlights new challenges and opportunities for businesses. This paper reviews the literature to understand the ability of sustainable green initiatives when practiced as a corporate culture to individually create new opportunities for operations, management and marketing. According to current research, business opportunities exclusively available to different functions of a firm can drive its performance. The role of marketing in the achievement of superior performance by virtue of sustainability practices is also explained by the existing literature. Branding literature, however, fails to explain the influence of a brand on sustainability-driven opportunities available to a firm for superior performance. The objective of this study is to explore if a brand can strengthen the ability of sustainability-based green initiatives of managers to drive opportunities available to a firm for superior performance. A conceptual framework grounded in the triple bottom line theory is presented based on the assumption that brand as a stimulating factor can accelerate the conversion of opportunities available to a business into superior performance. Academic and managerial perspectives have been used to draw upon the implications of the model. Both practitioners and academic researchers will benefit from future research on this topic

    Limiting worker exposure to highly pathogenic avian influenza a (H5N1): a repeat survey at a rendering plant processing infected poultry carcasses in the UK

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    <p>Abstract</p> <p>Background</p> <p>Current occupational and public health guidance does not distinguish between rendering plant workers and cullers/poultry workers in terms of infection risk in their respective roles during highly pathogenic avian influenza poultry outbreaks. We describe an operational approach to human health risk assessment decision making at a large rendering plant processing poultry carcasses stemming from two separate highly pathogenic avian influenza A (H5N1) outbreaks in England during 2007.</p> <p>Methods</p> <p>During the first incident a uniform approach assigned equal exposure risk to all rendering workers in or near the production line. A task based exposure assessment approach was adopted during the second incident based on a hierarchy of occupational activities and potential for infection exposure. Workers assessed as being at risk of infection were offered personal protective equipment; pre-exposure antiviral prophylaxis; seasonal influenza immunisation; hygiene advice; and health monitoring. A repeat survey design was employed to compare the two risk assessment approaches, with allocation of antiviral prophylaxis as the main outcome variable.</p> <p>Results</p> <p>Task based exposure assessment during the second incident reduced the number of workers assessed at risk of infection from 72 to 55 (24% reduction) when compared to the first incident. No cases of influenza like illness were reported in workers during both incidents.</p> <p>Conclusions</p> <p>Task based exposure assessment informs a proportionate public health response in rendering plant workers during highly pathogenic avian influenza H5N1 outbreaks, and reduces reliance on extensive antiviral prophylaxis.</p

    Hypothermia for encephalopathy in low and middle-income countries (HELIX): Study protocol for a randomised controlled trial

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    BACKGROUND: Therapeutic hypothermia reduces death and disability after moderate or severe neonatal encephalopathy in high-income countries and is used as standard therapy in these settings. However, the safety and efficacy of cooling therapy in low- and middle-income countries (LMICs), where 99% of the disease burden occurs, remains unclear. We will examine whether whole body cooling reduces death or neurodisability at 18-22 months after neonatal encephalopathy, in LMICs. METHODS: We will randomly allocate 408 term or near-term babies (aged ≤ 6 h) with moderate or severe neonatal encephalopathy admitted to public sector neonatal units in LMIC countries (India, Bangladesh or Sri Lanka), to either usual care alone or whole-body cooling with usual care. Babies allocated to the cooling arm will have core body temperature maintained at 33.5 °C using a servo-controlled cooling device for 72 h, followed by re-warming at 0.5 °C per hour. All babies will have detailed infection screening at the time of recruitment and 3 Telsa cerebral magnetic resonance imaging and spectroscopy at 1-2 weeks after birth. Our primary endpoint is death or moderate or severe disability at the age of 18 months. DISCUSSION: Upon completion, HELIX will be the largest cooling trial in neonatal encephalopathy and will provide a definitive answer regarding the safety and efficacy of cooling therapy for neonatal encephalopathy in LMICs. The trial will also provide important data about the influence of co-existent perinatal infection on the efficacy of hypothermic neuroprotection. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02387385. Registered on 27 February 2015
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