The political dimension of seasonal allocations: Developing a seasonal allocation strategy in a water-short system in Sri Lanka

Water allocation, Irrigation programs, Reservoirs, Participatory management, Farmer participation, Water rights, Irrigated farming, Rice, Water shortage, Farmers' attitudes, Farmer-agency interactions, Sri Lanka

Developing effective institutions for water resources management: A case study in the Deduru Oya Basin, Sri Lanka

River basins / Water resource management / Water lifting / Wells / Domestic water / Population / Economic aspects / Income / Irrigation programs / Institutions / Policy / Groundwater / Agricultural development / Fish farming / Pumps / Ecology / Water supply / Drought / Poverty / Land use / Water scarcity / Natural resources / Agricultural production / Cropping systems

Natural Resistance of Sri Lankan Rice (Oryza sativa L.) Varieties to Broad-Spectrum Herbicides (Glyphosate and Glufosinate)

Since studies on herbicide-resistant rice (HRR) are limited in Sri Lanka, the present study conducted to screen the naturally existing glyphosate and glufosinate resistance in traditional and inbred rice varieties. Six traditional varieties and nineteen inbred lines were selected for the study. Complete randomized design with three pots with 10 replicates for each herbicide concentration was employed. Optimal concentrations of glyphosate (0.5 gl−1) and glufosinate (0.05 gl−1) were applied at 3–4 leaf stages. Varieties ≥50% survival percentage was considered as resistant to respective herbicides. Twelve varieties showed resistance (≥50%) at 0.5 gl−1 glyphosate concentration. Survived plants were monitored and agro-morphological and yield characters/parameters were measured. Fifteen varieties were to glufosinate at 0.05 gl−1. Even though no significant differences (p > 0.05) were observed in growth parameters across control and treated plants, there was a yield penalty. Nine varieties (At362, Bg352, Bg359, Bg366, Bg369, Bg379-2, Bg403, Bg454, and Pachchaperumal) indicated moderate resistance to both glyphosate and glufosinate. The emerged HRRs indicated varying responses of agro-morphological and yield characters across the type of herbicide and the variety. Glyphosate reduced the growth parameters and yield penalty compared to glufosinate treated varieties. These HRR varieties have a higher potential in rice breeding programs and in developing HR rice varieties in future

Cost-Effectiveness of LDL-C Lowering With Evolocumab in Patients With High Cardiovascular Risk in the United States

Randomized trials have shown marked reductions in low-density lipoprotein cholesterol (LDL-C), a risk factor for cardiovascular disease (CVD), when evolocumab is administered. We hypothesized that evolocumab added to standard of care (SOC) vs SOC alone is cost-effective in the treatment of patients with heterozygous familial hypercholesterolemia (HeFH) or atherosclerotic CVD (ASCVD) with or without statin intolerance and LDL-C >100 mg/dL. Using a Markov cohort state transition model, primary and recurrent CVD event rates were predicted considering population-specific trial-based mean risk factors and calibrated against observed rates in the real world. The LDL-C–lowering effect from population-specific phase 3 randomized studies for evolocumab was used together with estimated LDL-C–lowering effect on CVD event rates per 38.67-mg/dL LDL-C lowering from a statin-trial meta-analysis. Costs and utilities were included from published sources. Evolocumab treatment was associated with both increased cost and improved quality-adjusted life-years (QALY): HeFH (incremental cost: US$153 289, incremental QALY: 2.02, incremental cost-effectiveness ratio: US$75 863/QALY); ASCVD (US$158 307, 1.12, US$141 699/QALY); and ASCVD with statin intolerance (US$136 903, 1.36, US$100 309/QALY). Evolocumab met both the American College of Cardiology/American Heart Association (ACC/AHA) and World Health Organization (WHO) thresholds in each population evaluated. Sensitivity and scenario analyses confirmed that model results were robust to changes in model parameters. Among patients with HeFH and ASCVD with or without statin intolerance, evolocumab added to SOC may provide a cost-effective treatment option for lowering LDL-C using ACC/AHA intermediate/high value and WHO cost-effectiveness thresholds. More definitive information on the clinical and economic value of evolocumab will be available from the forthcoming CVD outcomes study

Characterization of egg white gel microstructure and its relationship with pepsin diffusivity

Understanding the diffusion of digestive enzymes, particularly pepsin, in different food structures, is a key factorto better control protein digestion and absorption. This study aimed to investigate how protein-based foodmicrostructure impacts pepsin diffusion. Two egg white gels (EWGs) of identical protein concentration (10%)but different structures were used as food models. The two different gel structures were prepared by heatingliquid egg white at pH5 and pH9, respectively. Results showed that egg white proteins formed a compact andmicrostructurally homogeneous gel at pH9 (mean particle size of 0.32 ± 0.02 μm, with a mean interparticledistance of 0.76 ± 0.07 μm), which leads to a lower FITC-pepsin diffusion coefficient(Deff=44.2 ± 6.1 μm2 s−1), compared to the pH5-EWG (Deff=52.5 ± 5.3 μm2 s−1). The microstructure ofthe pH5-EWG was characterised by a spatially heterogeneous loose protein matrix made of larger aggregateparticles (mean particle size of 0.76 ± 0.07 μm, with a mean interparticle distance of 1.79 ± 0.57 μm). Inaddition to the effects of the EWG microstructure, the environmental pH also affects the FITC-pepsin diffusion,likely because of the impact on electrostatic interactions between pepsin and the egg white proteins

Rotation Measure Synthesis of Galactic Polarized Emission with the DRAO 26-m Telescope

Radio polarimetry at decimetre wavelengths is the principal source of information on the Galactic magnetic field. The diffuse polarized emission is strongly influenced by Faraday rotation in the magneto-ionic medium and rotation measure is the prime quantity of interest, implying that all Stokes parameters must be measured over wide frequency bands with many frequency channels. The DRAO 26-m Telescope has been equipped with a wideband feed, a polarization transducer to deliver both hands of circular polarization, and a receiver, all operating from 1277 to 1762 MHz. Half-power beamwidth is between 40 and 30 arcminutes. A digital FPGA spectrometer, based on commercially available components, produces all Stokes parameters in 2048 frequency channels over a 485-MHz bandwidth. Signals are digitized to 8 bits and a Fast Fourier Transform is applied to each data stream. Stokes parameters are then generated in each frequency channel. This instrument is in use at DRAO for a Northern sky polarization survey. Observations consist of scans up and down the Meridian at a drive rate of 0.9 degree per minute to give complete coverage of the sky between declinations -30 degree and 90 degree. This paper presents a complete description of the receiver and data acquisition system. Only a small fraction of the frequency band of operation is allocated for radio astronomy, and about 20 percent of the data are lost to interference. The first 8 percent of data from the survey are used for a proof-of-concept study, which has led to the first application of Rotation Measure Synthesis to the diffuse Galactic emission obtained with a single-antenna telescope. We find rotation measure values for the diffuse emission as high as approximately 100 rad per square metre, much higher than recorded in earlier work.Comment: Accepted for publication in The Astronomical Journa

Towards a new philosophy of engineering: structuring the complex problems from the sustainability discourse

This dissertation considers three broad issues which emerge from the sustainability discourse. First is the nature of the discourse itself, particularly the underlying philosophical positions which are represented. Second, is the nature of the highly complex types of problem which the discourse exposes. And third is whether the engineering profession, as it is practised currently, is adequate to deal with such problems. The sustainability discourse exposes two distinct, fundamentally irreconcilable philosophical positions. The first, “sustainable development”, considers humanity to be privileged in relation to all other species and ecosystems. It is only incumbent upon us to look after the environment to the extent to which it is in our interests to do so. The second, “sustainability”, sees humanity as having no special moral privilege and recognises the moral status of other species, ecosystems, and even wilderness areas. Thus, sustainability imposes upon us a moral obligation to take their status into account and not to degrade or to destroy them. These two conflicting positions give rise to extremely complex problems. An innovative taxonomy of problem complexity has been developed which identifies three broad categories of problem. Of particular interest in this dissertation is the most complex of these, referred to here as the Type 3 problem. The Type 3 problem recognises the systemic complexity of the problem situation but also includes differences of the domain of interests as a fundamental, constituent part of the problem itself. Hence, established systems analysis techniques and reductionist approaches do not work. The domain of interests will typically have disparate ideas and positions, which may be entirely irreconcilable. The dissertation explores the development of philosophy of science, particularly in the last 70 years. It is noted that, unlike the philosophy of science, the philosophy of engineering has not been influenced by developments of critical theory, cultural theory, and postmodernism, which have had significant impact in late 20th-century Western society. This is seen as a constraint on the practice of engineering. Thus, a set of philosophical principles for sustainable engineering practice is developed. Such a change in the philosophy underlying the practice of engineering is seen as necessary if engineers are to engage with and contribute to the resolution of Type 3 problems. Two particular challenges must be overcome, if Type 3 problems are to be satisfactorily resolved. First, issues of belief, values, and morals are central to this problem type and must be included in problem consideration. And second, the problem situation is usually so complex that it challenges the capacity of human cognition to deal with it. Consequently, extensive consideration is given to cognitive and behavioural psychology, in particular to choice, judgement and decision-making in uncertainty. A novel problem-structuring approach is developed on three levels. A set philosophical foundation is established; a theoretical framework, based on general systems theory and established behavioural and cognitive psychological theory, is devised; and a set of tools is proposed to model Type 3 complex problems as a dynamic systems. The approach is different to other systems approaches, in that it enables qualitative exploration of the system to plausible, hypothetical disturbances. The problem-structuring approach is applied in a case study, which relates to the development of a water subsystem for a major metropolis (Sydney, Australia). The technique is also used to critique existing infrastructure planning processes and to propose an alternative approach

SOIL ORGANIC MATTER AND WET AGGREGATE STABILITY IN TSUNAMI AFFECTED SOILS IN HAMBANTOTA DISTRICT, SOUTHERN SRI LANKA

Seawater intrusion occurred due the recent tsunami disaster badly affected onagricultural lands causing failure in crop production. Apart from elevatingsalinity level, addition of sodium ion with sea water creates dispersion of soilparticles, destroying it's aggregates or the structure, prompting immediateneed of rehabilitating the affected lands in order to sustain the productivity.Therefore the objective of the present study was to assess the impact oftsunami on Soil Organic Matter (SOM) and wet aggregate stability of theaffected soils in Hambantota district.Random soil samples were drawn from top 15cm soil depth, two weeks aftertsunami and analysed for SOM, wet aggregate stability (measured as MeanWeight Diameter or MWD) and aggregate distribution. Soil samples takenfrom a nearest unaffected field on the same soil type were used as thereference to compare the affected and unaffected soils.The average SOM contents of 0.27% and 1.06% respectively for the tsunamiaffectedsoils and the reference unaffected soil revealed a greater reduction ofSOM as a consequence of seawater intrusion. It could be explained theresults that removal of SOM by means of soil erosion and/or deposition oflarge amounts of sand dunes. According to the results, the highest MWD wasobserved from unaffected soil, while the lowest values found in affectedsoils. Furthermore, it can be seen a positive correlation between SOM andwet aggregate stability indicating an urgent need to improve soil managementpractices that increase SOM levels, and as a result, increase the soil aggregatestability in order to ensure sustained crop production in affected soils inHambantota district.

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

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