A review on microbial and toxic risk analysis procedure for reclaimed wastewater irrigation on paddy rice field proposed for South Korea

Water shortage has become a major agricultural concern, and “The Sustainable Water Resources Research Program” in Korea is currently addressing this problem through the development of treatment systems for reclaiming wastewater and the assessment of human health risks associated with its reuse. Through this program, started in 2001, many studies have examined various water resources. Reclaiming wastewater is one way to alleviate water-shortage pressures, and one of the major potential uses of reclaimed water is irrigation. However, the main concern with reusing reclaimed wastewater is the increased likelihood of human contact that might result in exposure to pathogens and increased health risks. Relatively few studies have examined the toxic risks using reclaimed wastewater for irrigation in rice paddy fields. This study provides an overview of methods for quantitative microbial risk assessment and toxic risk assessment of heavy metal concentrations developed in the previous studies that can be applied to the evaluation of rice paddy fields irrigated with reclaimed wastewater in South Korea.     

桉树叶中黄酮类的提取及其在农业上的应用

本文报导了从桉树叶中提取黄酮类物质的工艺。采用单罐提取,产品得率为30％左右;三罐组或五罐组逆流浸提,产品得率可达35％;提取的黄酮类物质能调节蔬菜和果树的生长,对植物的病害和病毒都有一定的防治效果。     

A new ent-kaurane diterpenoid from Croton tonkinensis leaves

A new ent-kaurane diterpenoid (1) was isolated from the leaves of Croton tonkinensis. The structure of 1 was determined as ent-7beta-hydroxy-15-oxokaur-16-en-18-ol from spectroscopic methods.     

Papyriflavonol A, a new prenylated flavonol from Broussonetia papyrifera

A new prenylated flavonol, papyriflavonol A, was isolated from the root barks of Broussonetia papyrifera. The structure of this compound was elucidated as 5,7,3',4'-tetrahydroxy-6,5'-di-(gamma,gamma-dimethylallyl)-flavonol (1) by spectroscopic analysis.     

Quality and decomposition of black locust (Robinia pseudoacacia) and alfalfa (Medicago sativa) mulch for temperate alley cropping systems

Black locust and alfalfa mulch quality were characterized over a 9-week period of decomposition. Both mulch materials were harvested with a forage harvester. The black locust material was harvested from trees annually coppiced for four years, the alfalfa from a preflorescent second cutting. Two identical, adjacent experiments were conducted, one on each mulch source. A randomized complete block design was used with four replications for this single factor experiment. Fifty grams fresh weight of both mulch types were placed in litter bags, made of 98% shade cloth, a woven plastic with holes approximately 1×0.5 mm. The treatments included two placements of the mulch material, surface and buried. Sampling took place on weeks 0, 1, 3, 6, and 9.The incorporation of mulch materials appears to accelerate dry weight loss. From an initial dry weight of 44.25 g, the buried black locust mulch averaged 4.58 g, while the surface mulch averaged 7.41 g by week 6. The alfalfa mulch initially weighed 40.99g, with buried mulch averaging 1.75 g and surface mulch averaging 4.08 g by week 9.Carbon concentration of alfalfa mulch increased with time in both mulch placements from 43.6% to 57.6% and 51.8% in surface and buried mulch, respectively. Black locust, with an initial carbon concentration of 46.9% increased to 55.9% for the buried mulch and to 53.89% in surface mulch. Nitrogen concentrations increased as well in buried mulch. Lignin concentrations increased dramatically over time for both species of mulch. Black locust lignin concentrations rose from 13.11% to 51.0% (buried) and 32.9% (surface); alfalfa mulch lignin concentrations rose from 6.67% to 31.4% (buried) and 47.7% (surface).     

Antibacterial and antifungal activity of Indonesian ethnomedical plants

Methylene chloride and methanol extracts of 20 Indonesian plants with ethnomedical uses have been assessed for in vitro antibacterial and antifungal properties by disk diffusion method. Extracts of the six plants: Terminalia catappa, Swietenia mahagoni Jacq., Phyllanthus acuminatus, Ipomoea spp., Tylophora asthmatica and Hyptis brevipes demonstrated high activity in this bioassay system. These findings should stimulate the search for novel, natural product such as new antibacterial and antifungal agents.     

Cytotoxic constituents from Plumbago zeylanica

The bioassay-guided fractionation of the dichloromethane extract of aerial parts of Plumbago zeylanica led to the isolation of beta-sitosterol, beta-sitosteryl-3beta-glucopyranoside, beta-sitosteryl-3beta-glucopyranoside-6'-O-palmitate (1), lupenone, lupeol acetate, plumbagin and trilinolein. Compound 1 showed cytotoxic activity against MCF7 and Bowes cancer cell lines (IC50 113 microM and 152 microM, respectively), beta-sitosterol inhibited Bowes cell growth (IC50 36.5 microM) and plumbagin was cytotoxic against MCF7 and Bowes cells (IC50 1.28 microM and 1.39 microM, respectively).     

A case study of forest management planning using a new heuristic algorithm

We present an approach to generate and evaluate different silvicultural development paths and to optimize the development of a Norway spruce stand, using a long-term planning horizon. To generate a silvicultural path, the maximum stand density was applied. At each thinning event, three possible thinning intensities (10, 20, 30% of the stem number per ha) were randomly chosen. A search algorithm known as modified Accelerated Simulated Annealing (mASA) was used to estimate the optimum combination of stand paths for a given forest as a whole. Production and economic management objectives were considered and then compared. The economic criterion was the Expected Stand Value (ESV) with a 4% discount rate. The generated data set of 38 Norway spruce stands (comprising a total of 123.8 ha) was used in the case study. The result with the best combination of paths was presented in a digitized forest map. Forest management simulation was performed using a specially developed computer program, for a planning horizon of 20 years. The mASA proved to be an effective search method for identifying optimum paths.     

Crinum L. (Amaryllidaceae)

Alkaloids isolated from Crinum species have been reviewed for the period 1985-2000. Non-nitrogenous compounds have been surveyed for the first time. Botanical classification and biological activity are discussed. Spectral data literature sources are listed.