University of Peradeniya

About: University of Peradeniya is a education organization based out in Kandy, Sri Lanka. It is known for research contribution in the topics: Population & Poison control. The organization has 5970 authors who have published 7388 publications receiving 197002 citations.

Climate sensitive size-dependent survival in tropical trees

Abstract: Survival rates of large trees determine forest biomass dynamics. Survival rates of small trees have been linked to mechanisms that maintain biodiversity across tropical forests. How species survival rates change with size offers insight into the links between biodiversity and ecosystem function across tropical forests. We tested patterns of size-dependent tree survival across the tropics using data from 1,781 species and over 2 million individuals to assess whether tropical forests can be characterized by size-dependent life-history survival strategies. We found that species were classifiable into four ‘survival modes’ that explain life-history variation that shapes carbon cycling and the relative abundance within forests. Frequently collected functional traits, such as wood density, leaf mass per area and seed mass, were not generally predictive of the survival modes of species. Mean annual temperature and cumulative water deficit predicted the proportion of biomass of survival modes, indicating important links between evolutionary strategies, climate and carbon cycling. The application of survival modes in demographic simulations predicted biomass change across forest sites. Our results reveal globally identifiable size-dependent survival strategies that differ across diverse systems in a consistent way. The abundance of survival modes and interaction with climate ultimately determine forest structure, carbon storage in biomass and future forest trajectories.

Effects of Microwave Heating and Gamma Irradiation on Phytate and Phospholipid Contents of Soybean (Glycine max. L.)

Abstract: The effect of microwave heating and gamma irradiation treatments on phosphorus compounds of soybean seeds were studied. Inorganic phosphorus was significantly (P < 0.05) increased while, phytate and phospholipids were significantly decreased when soybean seeds were microwave-heated for 9 min or more. Furthermore, gamma-irradiation treatments of 20 KGy or more significantly increased inorganic phosphorus and decreased phytate and phospholipids of the beans. Two dimensional thin-layer chromatography was employed to study the phospholipid pattern. Gamma-irradiation at doses from 40 to 100 KGy produced lysophosphatidylcholine and phosphatidic acid. The data of this study showed that, the increase of inorganic phosphorus was mainly due to the decomposition of phytic acids and phosphates of inositol.

Effect of postharvest calcium chloride vacuum infiltration on the shelf life and quality of tomato (cv. 'thilina')

Abstract: Mature turning tomato fruits (cv. ‘Thilina') were treated with four different concentrations of CaCl 2 (0%, 2%, 4%, and 6% aqueous solutions) using different modes of application; dipping, vacuum infiltration and pressure infiltration, with a view to improve the shelf life and quality. Fruits vacuum infiltrated at -20 kPa and treated with the four different concentrations of CaCl 2 were assessed for pH, total soluble solids (TSS) content, percentage titratable acidity (%TA) and firmness. Total calcium content in the inner and outer pericarp tissues was estimated and the path of calcium infiltration was revealed using black ink. Vacuum infiltration was found to be the most effective treatment with respect to shelf life extension. Also, 6% CaCl 2 treatment at -20 kPa was the best in terms of extension of shelf life (by 92%) and in keeping the postharvest quality of tomatoes compared to the untreated fruits kept at 28°C. Fruit firmness significantly increased with CaCl 2 application. Delay in fruit colour development, lowering of ethylene production rates and delay in the time taken to reach the ethylene climacteric were observed with increased CaCl 2 concentration. Treatment with CaCl 2 did not have a considerable effect on fruit pH, TSS or %TA. The amount of total calcium in the inner and outer pericarp regions increased significantly with calcium application. The stem end scar was found to be the main pathway of CaCl 2 infiltration in to fruits. Key words: firmness; ethylene; ripening DOI: 10.4038/cjsbs.v39i1.2351 Cey. J. Sci. (Bio. Sci.) 39 (1): 35-44, 2010

The impact of aluminum, fluoride, and aluminum–fluoride complexes in drinking water on chronic kidney disease

Abstract: It is suspected that drinking water containing fluo- ride and aluminum results in negative health effects especially onbrain,liver,and kidney.Inthisinvestigation,theeffectofF, Al, and AlFx complex on chronic kidney disease (CKD) was investigated.MiceweretreatedeitherwithWHOrecommend- ed or slightly higher F and Al levels in drinking water. Treatment solutions contained 0.05-10.0 mg/L of F, 0.08- 10.0 mg/L of Al, or 0.07-15 mg/L of AlFx, and the treatment period was 42 weeks. Blood urea level and creatinine levels were investigated as a measure of malfunction of kidneys. Histopathological evaluations of kidney tissues were carried out to assess the extent of damage that F, Al, and AlFx com- plexcould cause.Itwas demonstratedthatthe treated drinking water containing F and Al with par with WHO or moderately above the WHO levels or AlFx in low level (0.07-15 mg/L) does not lead to CKD in mice.