Physical and nutritional characteristics of less common traditional rice (Oryza sativa L.) varieties of Sri Lanka

Consumption and cultivation of traditional rice varieties have increased considerably in recent years due to the increased prevalence of non-communicable diseases in our country. However, the physical properties and nutritional composition of most traditional rice have not been scientifically studied to a satisfactory level. Therefore, this study determined the physical and nutritional properties of some less common rice varieties namely Pokkali, Murugakayan, Rathdel, Madathawalu, Kuruluthuda, Pachchaperumal, Suduheenati, Suwadel and Kaluheenati without subjecting to processing treatments such as polishing and parboiling. Length, width, thickness, diameter, volume and length/ width (shape) ratios as physical properties and moisture content, ash, crude fat and protein, total and digestible carbohydrate contents, resistant starch and insoluble soluble and total dietary fiber contents were determined according to standard methods. Length, width, and thickness of grains varied between 4.0- 6.4 mm, 2.2-2.9 mm and 1.5-2.2 mm respectively. Diameter, volume and length-width ratio were between 2.4-3.3 mm, 3.8-10.5 mm3 and 1.7-2.6 respectively. Accordingly, the varieties were categorized as bold or medium. Moisture contents of varieties were between 5.4-8.3% and ash contents less than 2% (DM). Low crude fat (4.2-4.9% DM) and high protein (5.5-9.2% DM) contents were observed. Digestible carbohydrate and total carbohydrate contents ranged between 77.5-84.6% (DM) and 79.1-85.2% (DM) respectively. Resistant starch content varied between 0.4- 3.2%. Corresponding insoluble, soluble and total dietary fiber contents ranged between 2.8-4.9%, 1.5-2.7% and 4.3-6.5% (DM). According to the data obtained the studied traditional rice varietiesare good sources of digestible carbohydrate, protein with low fat and moisture.KEYWORDS: Nutritional properties, physical properties, traditional ric

Incorporating appliance usage patterns for non-intrusive load monitoring and load forecasting

This paper proposes a novel Non-Intrusive Load Monitoring (NILM) method which incorporates appliance usage patterns (AUPs) to improve performance of active load identi- fication and forecasting. In the first stage, the AUPs of a given residence were learnt using a spectral decomposition based standard NILM algorithm. Then, learnt AUPs were utilized to bias the priori probabilities of the appliances through a specifically constructed fuzzy system. The AUPs contain likelihood measures for each appliance to be active at the present instant based on the recent activity/inactivity of appliances and the time of day. Hence, the priori probabilities determined through the AUPs increase the active load identification accuracy of the NILM algorithm. The proposed method was successfully tested for two standard databases containing real household measurements in USA and Germany. The proposed method demonstrates an improvement in active load estimation when applied to the aforementioned databases as the proposed method augments the smart meter readings with the behavioral trends obtained from AUPs. Furthermore, a residential power consumption forecasting mechanism, which can predict the total active power demand of an aggregated set of houses, five minutes ahead of real time, was successfully formulated and implemented utilizing the proposed AUP based technique

Associated risk factors in Breast cancer: A comparative Sri Lankan perspective

Breast cancer (BC) is the commonest carcinoma among women in Sri Lanka. Various modifiable and non-modifiable risk factors are reported as causatives of BC, even though studies on the incidence and relevance of these risk factors to the Sri Lankan context are not comprehensively documented. Thus, objectives of the present study were to assess the odds related to the incidence of known and unknown risk factors in BC development in Sri Lanka. The risk factors including age at diagnosis of BC, age at menarche, age at menopause, parity, duration of breastfeeding, history of abortions, usage of hormonal contraceptives, smoking, involvement of exercises, frequency of consumption of selected foods etc. were collected from an interviewer-administered questionnaire from 355 participants (255 BC patients and 150 healthy women). Ethical approval for the study was obtained. The majority (63%) of the BC patients were postmenopausal and the commonest age group at diagnosis of the carcinoma was 51-60 years. A woman was observed to have 3.6 (Odds Ratio= 3.58, Confidence Interval 1.37-9.34) and 2.1 (Odds Ratio 2.13, Confidence Interval 1.0-4.95) times risk in developing BC when_having first-order relatives and second-order relatives with breast cancer respectively. A woman had three times the odds (Odds Ratio= 3.02, Confidence Interval 1.59-5.75) of developing BC with the use of hormonal contraceptives for more than two consecutive years and three times the risk of _having BC (Odds Ratio= 3.12, Confidence Interval 1.63-5.98) if she has had one or more spontaneous or induced abortions. Factors including consumption of selected food, use of bottled water and usage of microwave ovens with inappropriate containers (plastic containers) among BC patients were not significantly different compared to healthy. The risk factors including a woman in the age close to or soon after menopause, having a family history of BC, having used hormonal contraceptives and having experienced one or more abortions showed a higher risk compared to other factors studied. KEYWORDS: Breast cancer, risk factors, family history, abortions, menopausal statu

Liver Toxicity of Raw and Processed Cycas circinalis (Madu) Seed Flour: An Animal Study

Various parts of Cycas circinalis (Sinhala: Madu) are used as food or in food preparation in many countries. Flour made from mature dried seeds is used in Sri Lanka to prepare starchy staples such as pittu and roti. However, the seeds are reported to contain hepato-toxins known as cycasins. This study was conducted to observe the liver toxicity, if any, of foods made incorporating cycas seed flour as data on effects of processing on liver toxicity are not available. The study was conducted with pittu and roti made by incorporating cycas seed flour obtained from soaked and dried seeds. Toxicity of pittu, roti and raw flour were observed by assessing the behavior of animals, liver enzymes and histopathological changes in liver sections of the mice fed diets made by incorporating pittu, roti and raw flour for 28 days. Significant elevations in liver enzymes (p<0.05) (reference AST 195 ± 38, ALT 21.2 ± 1.1 IU/L, raw flour AST 345 ± 71, ALT 50.8 ± 3.1 IU/L; pittu AST 406 ± 68, ALT 39.2 ± 1.1 IU/L; roti AST 333 ± 31, ALT 28.8 ± 1.5 IU/L) were observed in rats fed cycas flour incorporated diets. Fatty inclusions, few scattered lymphocytes and mild perpendicular inflammations were observed in the liver sections of all test groups. However, the elevation of liver enzymes and histopathological changes were significantly low (p<0.05) in mice fed with roti incorporated diet when compared to other test groups. Hence, the present study suggests that dry heat processing is detoxifying hepato-toxins in seeds to a certain extent. However, the present study confirms that continuous feeding of raw or processed cycas flour containing food could lead to liver parenchymal cell damage.KEYWORDS: Cycas circinalis, liver toxicity, cycasins, roti, pitt

Antioxidant, Antiglycation Potentials and Total Phenolic Content of Scoparia dulcis Decoction

Long term diabetes mellitus increases the risk of many micro and macro vascular diabetic complications and oxidative stress, due to formation of excessive amounts of free radicals. Non enzymatic protein glycation is the key molecular basis of the above complications observed in diabetic individuals. The current tendency to use herbal treatments in diabetes mellitus is mainly due to the therapeutic efficacy, safety, low cost and minimal adverse effects. Among the many herbs used, the decoction prepared using the whole plant of Scoparia dulcis is a frequently used traditional medicine in the treatment of diabetes mellitus.Since no data are available on the antiglycation potential of the decoction of S. dulcis plant this study focused on determining the antiglycation potential, DPPH and ABTS antioxidant potentials and total phenolic content of the S. dulcis decoction.The commercially available dried S. dulcis and three other fresh samples collected from three different areas were used for the study. The DPPH and ABTS antioxidant potentials of the samples were in the range of 450-540 μg mL-1 and 549-615 TEAC mmol g-1 respectively. Antiglycation potentials of the four samples were in the range of 131-230 μg mL-1 and total phenolic contents were 160-186 mg/GAE/g. The results of the study prove the effectiveness of the use of S. dulcis plant in traditional medicine for diabetes.Keywords: S. dulcis, decoction, antiglycation, antioxidant, phenolic contents, traditional medicin

Numerical simulation of a convergent divergent supersonic nozzle flow

Supersonic fluid flow through a two dimensional Convergent Divergent (CD) nozzle with angle variation added to the divergent section of the nozzle using ANSYS CFX. . Flow undergoes many forms of unique phenomena, including flow separation, unsteadiness, flow mixing, turbulence, Shock Induced Boundary Layer (SIBL) separation and Mach Shock Diamonds, when gas expanded through a CD nozzle. Some of these phenomena lead to energy loss, thereby reducing the overall thrust generated by the nozzle. The thrust loss due to shock waves and boundary layer separations in nozzle flows remains poorly understood, hence failed to reach maximum potential of an engine. In this research, two nozzle configurations, with two symmetric and two asymmetric geometry shapes are investigated. Asymmetric is introduced by adding contraction angles at the divergent section. Numerical analysis is focused on the influence of the nozzle geometry, the Nozzle Area Ratio (NAR) and Nozzle Pressure Ratio (NPR) on the flow properties downstream (divergent section) and the external (jet plume) region of the nozzle. Capturing the boundary layer flow characteristics under strong adverse pressure gradients is of particular interest of this study. The NAR is varied to investigate the gas flow direction and speed, for the asymmetric nozzle in Underexpanded conditions at high NPRs. The two symmetric model configurations, NAR 1.5 and NAR 1.66, have a divergent angle at the throat of 2.801 and 3.89 degrees respectively. The two asymmetric geometry configurations, NAR 1.14 and 1.21, consist of a divergent angle of 2.801 degrees at the throat with contraction angle variations in the divergent section. ANSYS CFX is used to solve time-dependent RANS equations for supersonic two dimensional (2D) nozzle flow with Shear Stress Transport (SST) turbulence model. The NPRs for both symmetric and asymmetric are varied between 1.27 – 12.0 under the sea-level condition for the steady state solutions. It is found that -under low NPRs, the SST model has transcended in performance to capture internal shocks, as well as boundary layer separation, re-circulation zones, shear layer stresses caused by strong adverse pressure gradients accurately in axis-symmetric nozzles. Typical Lambda shocks associated to internal flow separation is not observed for the asymmetry type model, NAR 1.21. Asymmetric nozzles have produced higher Mach number values - than that of symmetric - nozzles. The research has also found that when varying the divergent section of the asymmetric nozzles, the flow path is vectored away from the nozzle axis line at high NPRs. The flow is significantly offset in the desired direction and is considerably different from the traditional Mach Diamond shock pattern observed in symmetric nozzle shapes at the jet plume region. Asymmetric nozzle geometries have a major contribution towards the size of the Mach disks and Diamond shock patterns within the jet plume region. Varying the angle of the top and the bottom walls has a significant effect on the exhaust flow direction. This could be implemented in the future high speed nozzle designs

The synergistic neurotoxins of palmyrah (Borassus flabellifer L.) flour

Palmyrah (Borassus flabellifer L.) is consumed in various forms in different parts of Sri Lanka. Although a neurotoxic syndrome had been described in rats it is being consumed by humans. However, the chemical nature of the neurotoxin is unknown. Thus the objective of the present study was to determine the neurotoxic principle using palmyrah seed shoot and bioactivity directed separations. Two primary amines were isolated. These were not toxic individually but toxic when given together showing synergism. Studies of the amines by 1H NMR and 13C-NMR showed a steroidal aglycone (spirostane) linked to a carbohydrate moiety containing three a-rhamnosyl residues and a b-pyranosyl residue. Comparison with known spectral data showed that the b-pyranosyl is likely to be a β-glucosaminosyl which is probably in position 6 of glucose in one compound and most likely to be in the position 3 of glucose in the other. Synergism appears to be at two levels (i.e. at the absorption level) where the high content of neutral saponins present appears to be needed to facilitate absorption of the cationic toxin and at the point of action. The synergistic mechanism of the toxic amines remains to be explained