Monitoring of Atmospheric Mercury at a Global Atmospheric Watch (GAW) Site on An-Myun Island, Korea

In order to investigate the regional background concentration levels of mercury (Hg), measurements were routinely recorded on An-Myun Island off the coast of Korea (December 2004 to April 2006). The mean concentration of Hg computed from the entire measurement period was 4.61?±?2.21 ng m^?3 with a range of 0.10–25.4 ng m^?3 (N?=?10,485). Using these data, we inspected various aspects of Hg behavior from the relatively remote island of An-Myun in Korea. Inspection of the seasonal patterns of Hg indicated that its concentration levels generally peaked in spring, while reached a minimum in summer. The summertime deficiency of Hg along with the lack of diurnal variation suggests that the environmental behavior of Hg at the study site was strongly suppressed by heavy precipitation during specific period. The diurnal variations of Hg, typically characterized by a relative daytime dominance, are distinguishable between seasons so that such patterns disappear during the summer. The results of our analysis, when inspected in terms of long-range transport of airborne pollutants, imply that Hg concentration levels can be affected intensively by trans-boundary input processes over certain period of time. Its springtime dominance hence suggests the combined effects of various local source processes and the meteorological conditions favorable for the massive air mass transport phenomenon (such as Asian Dust storms) during that time period.     

Antioxidative compounds from the outer scales of onion

Antioxidative compounds were isolated from the methanol extract of dry outer scales of onion (Allium cepa L.). Nine phenolic compounds (1-9) were finally obtained by reversed-phase high-performance liquid chromatography, and their structures were elucidated by NMR and mass spectrometry analyses. They were the six known compounds, protocatechuic acid (1), 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (2), quercetin 4'-O-beta-D-glucopyranoside (3), quercetin (5), 4'-O-beta-d-glucopyranoside of quercetin dimer (7), and quercetin dimer (8), and three novel compounds, condensation products of quercetin with protocatechuic acid (4), adduct of quercetin with quercetin 4'-O-beta-D-glucopyranoside (6), and quercetin trimer (9). These phenolic compounds were tested for their antioxidant properties using autoxidation of methyl linoleate in bulk phase or free radical initiated peroxidation of soybean phosphatidylcholine in liposomes. The flavonoid compounds having o-dihydroxy substituent in the B-ring were shown to be effective antioxidants against nonenzymic lipid peroxidation.     

Isolation and characterization of some antioxidative compounds from the rhizomes of smaller galanga (Alpinia officinarum Hance)

Antioxidative compounds were isolated from the methanol extract of fresh rhizome of smaller galanga (Alpinia officinarum Hance). Seven phenylpropanoids (1-7) were finally obtained by reversed-phase HPLC, and their structures were elucidated by MS and NMR analyses. They comprised the two known compounds, (E)-p-coumaryl alcohol gamma-O-methyl ether (1) and (E)-p-coumaryl alcohol (6), and the five novel compounds, stereoisomers of (4E)-1,5-bis(4-hydroxyphenyl)-1-methoxy-2-(methoxymethyl)-4-pentene (2a and 2b), stereoisomers of (4E)-1,5-bis(4-hydroxyphenyl)-1-ethoxy-2-(methoxymethyl)-4-pentene (3a and 3b), (4E)-1,5-bis(4-hydroxyphenyl)-1-[(2E)-3-(4-acetoxyphenyl)-2-propenoxy]-2-(methoxymethyl)-4-pentene (4), (4E)-1,5-bis(4-hydroxyphenyl)-2-(methoxymethyl)-4-penten-1-ol (5), and (4E)-1,5-bis(4-hydroxyphenyl)-2-(hydroxymethyl)-4-penten-1-ol (7). Compounds 1-7 were detected for the first time as constituents of galanga rhizomes and exhibited antioxidative activities against the autoxidation of methyl linoleate in bulk phase.     

Main Characteristics of Statistical Data and the Statistical System for Wood and Wood-processing Products in Vietnam

This paper describes the characteristics of data about wood and wood-processing products published in Vietnam. The characteristics include inconsistency of data published by major data sources, lack of necessary data, and irregular publication frequency. Reasons are identified for the existence of the above characteristics of data for the wood and wood-processing industries, including recent changes in the functions of state statistical organizations and unclear concepts of data published. These characteristics create difficulties for researchers and policy-makers working at the Ministry of Agriculture and Rural Development for analysing policies and establishing supply targets for the wood and wood-processing industries in 5-year economic plans. To improve the statistical system, co-operation between state organisations and the information network (e.g. computers and internet connection) requires strengthening.     

Effects of permanent magnetic fields on the proliferation of Phalaenopsis protocorm-like bodies using liquid medium

Magnetic fields (MFs) have been applied for the first time in orchid micropropagation. Protocorm-like bodies (PLBs) – approximately 3 mm in diameter – first derived from leaf segment culture of Phalaenopsis Gallant Beau ‘George Vazquez’, were subcultured every 2 months, and served as initial explants. The proliferation of Phalaenopsis PLBs in liquid medium in the Miracle Pack^® culture system was affected by the action of different intensities and polarities of MFs: 0.1, 0.15 and 0.2 Tesla (T) at North (N) and South (S) poles. The MF of 0.1 T – S resulted in the greatest fresh weight of regenerated PLBs. The average number of neo-PLBs formed per clusters in the PLB treated by MF: 0.1–0.2 T was decreased compared to the control exposed to natural MF (5 × 10⁻⁶ T). The proliferation of PLBs under 0.15 T – MF at both N and S poles for 2 and 7 weeks demonstrated that a longer duration of exposure to an MF of 0.15 T, regardless of the polarity, resulted in greater biomass of newly formed PLBs and smaller average number of newly formed PLBs. The S pole of MF had stronger effects on Phalaenopsis PLBs proliferation than the N pole did in all treatments.     

Effect of drying and rewetting on phosphorus transformations in red brown soils with different soil organic matter content

In this study, the effect of drying and rewetting on native P transformations in two red brown soils with different management history was investigated. Three treatments, T1 (constantly moist), T2 (dried for 4 days and then kept dry), T3 (rewetted after 4 days drying) were used. Drying and rewetting caused a rapid increase in microbial P (Pm) and labile organic P (labile Po) within 1 day and a gradual increase in available inorganic P (Colwell). These increases were only temporarily, as Pm and labile Po decreased with time and were at the same level as in the constantly moist soil by the end of the incubation period of 21 days. The effect of drying and rewetting on P transformations strongly depended on soil organic matter content, being more pronounced in the soil with high organic matter content, compared to the soil with low soil organic matter content.     

Evaluation of fly ash,apatite and rice straw derived-biochar in varying combinations for in situ remediation of soils contaminated with multiple heavy metals

ABSTRACT

In

-situ sorbent amendment is a relatively low-cost, low-impact approach for remediation of soil contaminated with heavy metals (HMs), and thus is considered a way to be favored in developing countries. In this study, materials of non-hazardous, alkaline agronomic and industrial by-products were used as sorbents to explore their capacity of in situ immobilization of multiple HMs in mining-impacted arable soil. These sorbents included fly ash (FA), biochar (BC) and apatite (AP) and they were implemented with varying ratios of combinations. Results of soil microcosm tests showed that after incubation for 90 days, concentrations of Pb, Zn, and Cd in their exchangeable forms determined by a sequential extraction method significantly decreased in amended soils, as opposed to the unamended control. Of the five sets of amendments, the composite of FA, BC, and AP resulted in the maximum reduction (up to 80%) in the mobility of Pb, Zn, and Cd in soils. The mechanisms underlying the immobilization of HMs in amended soils might involve processes of surface precipitation, ion exchange and complexation, in which the physicochemical properties of sorbent materials played an important role. The immobilization efficacy of sorbent amendments on HMs in soil was further supported by pot experiments in which significant inhibition of HM accumulation in the belowground and aboveground tissues of maize was observed after 50-day cultivation in amended soils as compared with control soil. Together, these results suggest that the application of cost-saving and environmentally friendly materials derived from wastes as sorbents to remediate soils contaminated with multiple HMs is promising for developing countries like Vietnam.     

Anthropogenic Input of Selected Heavy Metals (Cu, Cr, Pb, Zn and Cd) in the Aquatic Sediments of Hochiminh City, Vietnam

The aquatic system of Hochiminh City comprises two main rivers: the Sai Gon and Nha Be rivers. Five canals discharge into these two rivers: NhieuLoc-ThiNghe, TauHu-BenNghe, TanHoa-LoGom, ThamLuong-BenCat and Doi-Te. The rivers and these canals collect effluent water from domestic and industrial sources. Most of these flows are not treated or at most are only primarily treated. A total of 33 sediment cores were taken from these rivers and canals. Chemical composition of these aquatic sediments has very high concentrations of several “urban” metals such as Cd, Cr, Cu and Zn. Most of the samples have exceeded the US EPA’s toxicity reference values for Cu, Zn and Cr (82, 82 and 70%, respectively). The highest concentrations of these metals appear to be associated with the uncontrolled and untreated industrial runoff to the discharge canals. These concentrations in fluvial sediment are relatively low, which indicates the dilution process of the contaminants. This finding indicates that the anthropogenic inputs play an important role in the elevation of heavy metals in the aquatic system and organic matter seems to exert a strong geochemical control on the amount of heavy metals. The Pearson correlation coefficients calculated for Cd, Cr, Cu and Zn, are 0.89; 0.72; 0.93 and 0.87, respectively.     

Assessing in vivo Fertilizing Capacity of Liquid-Preserved Boar Semen According to the 'Hanover Gilt Model'

The goal of this study was to determine the ability of the Hanover gilt model to assess in vivo fertilizing capacity of preserved sperm and to consider whether any modifications to this model were needed. This model evaluates the fertilizing capacity of semen based on the fertilization rate, the rate of normal embryos and the accessory sperm count of 3–5‐day embryos. Its distinguishing characteristics are the use of one‐time insemination of sperm in reduced numbers, of spontaneously ovulating gilts and of ovulation detection through ultrasound examination of ovaries. Reduced sperm numbers allow for an accurate evaluation of the fertilizing potential of different semen treatments, thereby avoiding the compensatory effect of doses calibrated to maximize fertility. The model's usefulness was assessed in a trial run designed to compare the fertilizing capacity of liquid boar semen diluted into two different extenders. The diluent, the boar and the backflow, had no significant effect on any of the parameters studied. Gilts inseminated less than 24 h before ovulation had a significantly higher (p < 0.01) fertilization rate and accessory sperm cell count (p < 0.05) than those inseminated more than 24 h before ovulation. Very good/good embryos from homogeneous litters (only very good/good embryos were present) had a significantly higher (p < 0.01) accessory sperm count than those from heterogeneous litters (at least one embryo was of a different quality and/or oocytes were present). Both very good/good and degenerated/retarded embryos from heterogeneous litters had low accessory sperm numbers. This suggests that accessory sperm count is significantly related to the quality of the litter, but not to the quality of the embryo within gilts. It can be concluded that the Hanover gilt model is sensitive enough to show fertility differences (in this study, those associated with in vivo ageing of semen), while using relatively few gilts and little time.