Seasonal variation of Ra/Ra ratio in seaweed: implications for water circulation patterns in coastal areas of the Noto Peninsula, Japan

To examine water circulation patterns of coastal water, 72 seaweed (Sargasso) samples and 27 coastal water samples were collected from coastal areas of the Noto Peninsula, Japan, during the period from December 1998 to June 2002. The (228)Ra and (226)Ra activities of those samples were measured by low-background gamma-ray spectrometry. There was a wide range of activities of (228)Ra (0.5-2Bq/kg-fresh) and (226)Ra (0.5-1.2Bq/kg-fresh) in the Sargasso samples. The (228)Ra/(226)Ra activity ratio of Sargasso samples exhibited seasonal variation with minimum values in June ((228)Ra/(226)Ra= approximately 1) and maximum values in December (1.5-2.5), which was mainly governed by changes in (228)Ra activity. It is also notable that the seasonal variation of the (228)Ra/(226)Ra ratio of Sargasso is in approximate agreement with that of the ambient coastal water. Sargasso samples appear to have retained the (228)Ra/(226)Ra ratio of the ambient coastal waters, and the temporal variations in that ratio provide insight into seasonal changes in water circulation in the Noto Peninsula coastal area.     

Studies on automated survey system of environmental chemicals by gas chromatography-mass spectrometry-computer III. Construction of an automated survey system and its application

An automated survey system on the chemicals in environments by a gas chromatography-mass spectrometry-computer system has been constructed of Three Dimensional Mass Chromatography, Modified Probability Based Matching method, and Self Training Interpretive and Retrieval method. And it was applied to analyze environmental materials, with interesting results.     

Surface water mixing estimated from 228Ra and 226Ra in the northwestern North Pacific

We investigated the horizontal distributions of (228)Ra and (226)Ra in surface waters of the northwestern North Pacific Ocean and Okhotsk Sea. Ratios of (228)Ra/(226)Ra were relatively large in the Tsugaru Current (0.6-0.8) and Okhotsk Sea (0.4-0.5), and small in the Western Subarctic Gyre (<0.2) and the Oyashio (0.25-0.3). (228)Ra/(226)Ra ratios in western Subarctic Water (SAW) rose slightly upon mixing with Okhotsk Water (OKW), before becoming the Oyashio Water (OYW). Also, ratios in the OYW increased during mixing with Tsugaru Current Water (TCW). Estimating from (228)Ra/(226)Ra ratios and (226)Ra activities with a simple two-end members-mixing model, we assumed that approximately 23% of the OYW originated from the OKW and the coastal region off northern Honshu (Japan) was strongly influenced by the TCW. From a diagram of (228)Ra activities against salinity, we could roughly divide surface seawater in the study area into the five water masses, which were SAW, OYW, OKW, TCW, and Subtropical Water (STW).     

A comparative evaluation of wet digestion and dry ashing methods for the determination of some major and minor nutrients in composted manure

The analytical results of 53 manure samples determined by wet digestion and dry ashing procedures were compared in order to evaluate their relative suitability for recovering different nutrient elements in manure and manure compost. Wet digestion recovered greater amounts of phosphorus (P), potassium (K), calcium (Ca), manganese (Mn), and zinc (Zn) in more samples than dry ashing. Nutrient contents in the samples were highly variable, with coefficients of variation (CV) ranging from 38% for magnesium (Mg) to 161% for copper (Cu) analyzed by the wet digestion procedure, and from 47% to 138% for Mg and Cu analyzed by the dry ashing procedure. The mean values of P, K, Ca, Mn, and Zn averaged for the 53 samples were significantly higher using wet digestion than dry ashing procedure, but both procedures recovered comparable amounts of iorn (Fe), Mg, and Cu. Correlations analysis between both procedures for each element showed reasonable to fair agreements for Ca (R ²?=?0.93), K (R ²?=?0.93), P (R ²?=?0.90), Mg (R ²?=?0.84), Fe (R ²?=?0.87), Mn (R ²?=?0.73), and Cu (R ²?=?0.66), but poor agreement for Zn (R ²?=?0.44). The low agreement between procedures for Zn suggests that wet digestion, which gave a higher recovery, should be a preferred procedure for analyzing Zn in manures.     

Estimation of municipal solid waste generation and landfill area in Asian developing countries

In developing Asian countries, the municipal cooperations are unable to handle the increasing amount of municipal solid waste, which into the uncollected waste being spread on roads and in other public areas leading to tremendous pollution and destruction of land and negative impact on human health. Generation of municipal solid waste increases with the rapid urbanization and accelerated economic development with in the rapidly growing advanced technological societies. The nature of municipal solid waste is a term usually applied to a heterogeneous collection group of waste produced in urban areas, the nature of which varies from region to region. The common problem faced by all developing Asian countries, is the disposal of municipal solid waste and availability of land fill site area. Present study explains the correlation analysis of among different factors of municipal solid waste and the objective is to assess the future municipal solid waste stream in Asian developing countries. The other goal of this study was to calculate the future land area that would be required for landfill site disposal in Asian developing countries.     

Comparison of polybrominated diphenyl ethers in fish, vegetables, and meats and levels in human milk of nursing women in Japan

At present, little is known about the occurrence of polybrominated diphenyl ethers (PBDEs) in fish and food products sold in Japan. To investigate whether human exposure to PBDEs through the diet is significant, the concentrations of PBDEs were determined in fish and in meat and vegetables sold in two food markets in the city of Hirakata, Osaka prefecture. The concentrations of PBDEs in the breast milk of 12 primiparae nursing women at one month after delivery also were determined to ascertain the relationship between the levels found in the diet and levels in humans. sigma PBDE concentrations ranged between 21 and 1650 pg/g fresh weight in the edible tissues of five species of fish and one shellfish species. The highest concentrations were measured in yellow-fin tuna, followed by short-necked clam, salmon, yellowtail, mackerel and young yellowtail. Interestingly, sigma PBDE concentrations were not statistically significantly different in two cultured mackerel samples from Japan and mackerel collected from northern European waters. sigma PBDE concentrations in beef, pork and chicken meat (ranging between 6.25 and 63.6 pg/g fresh weight) and in three different vegetables (ranging between 38.4 and 134 pg/g fresh weight) were significantly lower than the concentrations in fish. In human milk, sigma PBDE concentrations ranged between 668 and 2840 pg/g lipid basis, which is comparable to the levels in populations of nursing women reported in Sweden and elsewhere. There was a strong positive relationship between PBDE concentrations in human milk and dietary intake of fish and shellfish, which was established in the women from responses to a questionaire on food consumption habits. The results of this study of food products commonly consumed in Japan and the levels found in nursing women raise a concern about low level PBDE contamination of fish and other foods intended for human consumption.     

Regional-specific emission inventory for NH3, N2O, and CH4 via animal farming in South, Southeast, and East Asia

Ammonia, nitrous oxide, and methane emission from animal farming of South, Southeast, and East Asia, in 2000, was estimated at about 4.7 Tg NH₃–N, 0.51 Tg N₂O–N, and 29.9 Tg CH₄, respectively, using the FAO database and countries’ statistic databases as activity data, and emission factors taking account of regional characteristics. Most of these atmospheric components, up to 60–80%, were produced in China and India. Pakistan, Bangladesh, and Indonesia, which were large source countries next to China and India, contributed more than a few percent of total emission of each atmospheric component. The largest emission livestock were cattle whose contribution was considerably high in South, Southeast, and East Asia; more than one-fourth of ammonia and nitrous oxide emissions: more than half of methane emission. The other major livestock for nitrous oxide and ammonia emissions were pigs. For methane emission, buffaloes were second source livestock. To provide spatial distributions of these gases, the emissions of county and district level were allocated into each 0.5° grid by means of the weighting by high-resolution land cover datasets. The regions with considerable high emissions of all components were able to be found at the Ganges delta and the Yellow River basin. The spatial distributions for ammonia and nitrous oxide emissions were similar but had a substantial difference from methane distribution.     

Regulation of bone morphogenetic proteins in early embryonic development

Bone morphogenetic proteins (BMPs), a large subgroup of the TGF- family of secreted growth factors, control fundamental events in early embryonic development, organogenesis and adult tissue homeostasis. The plethora of dose-dependent cellular processes regulated by BMP signalling demand a tight regulation of BMP activity. Over the last decade, a number of proteins have been identified that bind BMPs in the extracellular space and regulate the interaction of BMPs with their cognate receptors, including the secreted BMP antagonist Chordin. In the early vertebrate embryo, the localized secretion of BMP antagonists from the dorsal blastopore lip establishes a functional BMP signalling gradient that is required for the determination of the dorsoventral – or back to belly – body axis. In particular, inhibition of BMP activity is essential for the formation of neural tissue in the development of vertebrate and invertebrate embryos. Here we review recent studies that have provided new insight into the regulation of BMP signalling in the extracellular space. In particular, we discuss the recently identified Twisted gastrulation protein that modulates, in concert with metalloproteinases of the Tolloid family, the interaction of Chordin with BMP and a family of proteins that share structural similarities with Chordin in the respective BMP binding domains. In addition, genetic and functional studies in zebrafish and frog provide compelling evidence that the secreted protein Sizzled functionally interacts with the Chd–BMP pathway, despite being expressed ventrally in the early gastrula-stage embryo. These intriguing discoveries may have important implications, not only for our current concept of early embryonic patterning, but also for the regulation of BMP activity at later developmental stages and tissue homeostasis in the adult.     

Properties and biodegradability of chain-extended copoly(succinic anhydride/ethylene oxide)

Chain-extension reactions were carried out using titanium-iso-propoxide (TIP) as a catalyst for a series of polyesters or copolyesterethers with low molecular weights (M _n =1500–10,000) synthesized by the ring-opening copolymerization of succinic anhydride (SA) with ethylene oxide (EO). The copolymers having aM _n from 25,000 to 50,000 of different properties were obtained. Both the melting point (T _m ) and the fusion heat (H), which indicate the crystallinity of the copolymers, rose with an increase in SA content in the copolymers. Semitransparent films were prepared by compression molding of the copolymers. The biodegradation of the copolymer films was evaluated by enzymatic hydrolysis by lipases and by an aerobic gas evolution test in standard activated sludge. The hydrolyzability of these copolymers by three kinds of lipases was affected by their copolymer composition SA/EO, form, andM _n . The copolyesterether (SA/EO=43/57,M _n =48,900) was more easily biodegraded by standard activated sludge compared to the polyester (SA/EO=47/53,M _n =36,300).Presented at the Pacifichem-95, December 17–22, 1995, Honolulu, Hawaii.