Measuring Water Storage Fluctuations in Lake Dongting, China, by Topex/Poseidon Satellite Altimetry

Although satellite radar altimetry was developed and optimized for open oceans, it has been used to monitor variations in the level of inland water-bodies such as lakes and rivers. Here, for the first time, we have further used the altimetry-derived variation of water level for estimating the fluctuation of water storage as an addition to the present in situ water storage estimation systems to be used in remote areas and in emergency situation such as in the events flooding monitoring and for studying the effect of climate change. Lake Dongting, the second largest lake in China, influenced frequently by flooding, was, therefore, chosen to demonstrate the potential of the technique. By using the concept of an “assumed reference point”, we converted Topex/Poseidon satellite altimetry data on water level variations in Lake Dongting to “water level” data. The “water level” time-series data and in situ water storage were used to establish a rating curve. From the rating curve, we converted data on “water level” derived from seven years (1993–1999) of Topex/Poseidon data to actual water storage in Lake Dongting. The result reveals that the seasonal and annual fluctuations of water storage occurred during the 1990s with a more frequent flooding at the late 1990s' especially the flooding in whole catchment level in 1998 and 1999. The study supports the usefulness of satellite altimetry for dense and continuous monitoring of the temporal variations in water dynamic in moderate to large lakes.     

Oil adsorbent produced by the carbonization of rice husks

In this study, rice husks considered to be agricultural waste are converted into an adsorbent intended for use in the disposal of oil spills. The raw and refined (defiberized) husks of Japanese Akita Komachi rice were pyrolyzed in a vacuum (500 Pa) at 300-800 degrees C. The amount of A-heavy and B-heavy oils adsorbed on the carbonized rice husk were then evaluated. Oil adsorption is dependent on the type of oil. Rice husks refined and then pyrolyzed at 600-700 degrees C (1.0 g) adsorbed >6.0 g of B-heavy oil and <1.5 g of water, which indicates their usefulness as an adsorbent for oil spill cleanup in Japan. The refining process contributes to an improvement in the oil adsorption capacity, while the carbonization time (at 600 degrees C) has only a minor influence. The residual fluid components in the carbonized rice husks, rather than their porosity, are closely related to oil adsorption capacity.     

Prenatal diagnosis in a family with mitochondrial acetoacetyl-coenzyme a thiolase deficiency with the use of the polymerase chain reaction followed by the heteroduplex detection method

Mitochondrial acetoacetyl-coenzyme A (CoA) thiolase deficiency is an organic aciduria which affects isoleucine and ketone body catabolism. GK16 (the index patient) was affected with this disorder and previous studies had revealed that GK16 was a compound heterozygote with IVS8(+1) gt to tt and A301P mutations. In a subsequent pregnancy, prenatal diagnosis was performed and the fetus's amniocytes were analysed by the polymerase chain reaction (PCR) followed by the heteroduplex detection method on a Mutation Detection Enhancement gel. The fetus was identified as a carrier of the IVS8(+1) mutation. We confirmed the diagnosis by immunoblot analysis of extracted amniocytes and gene analysis with blood filter paper after delivery. This is the first report of prenatal diagnosis of this disorder at the gene level.     

Large-scale evaluation of the current level of polybrominated diphenyl ethers (PBDEs) in breast milk from 13 regions of Japan

Polybrominated diphenyl ethers (PBDEs) were measured in 2004 in 105 breast milk samples collected from 13 regions of Japan (Hokkaido, Akita, Miyagi, Tokyo, Gifu, Fukui, Kyoto, Hyogo, Wakayama, Shimane, Yamaguchi, Kochi and Okinawa). Six congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153 and BDE-154) were determined by gas chromatography /mass spectrometry (GC/MS). Total PBDE levels ranged from 0.01 to 23.0 ng/g lipid (geometric mean (GM), 1.34 ng/g lipid). BDE-47 (GM, 0.66 ng/g lipid, 59% of sigmaPBDE) was the most abundant congener present in breast milk and was detected in 99% of the samples. Total PBDE levels were higher in northern Japan than in other regions. We analyzed the effects of occupation, age, smoking status, alcohol consumption and number of deliveries on total PBDE levels. None of these factors were significantly associated with the level of PBDEs. The present study revealed that the current level of exposure to PBDEs in Japan is lower than that in the USA or Sweden. GMs (ng/g lipid) (GSD, geometric standard deviation) and medians (ng/g lipid) of PBDE levels in each district are as follows: Hokkaido 2.70 (1.70), 2.74; Akita 4.49 (2.19), 5.44; Miyagi 1.77 (4.37), 1.11; Tokyo 1.39 (2.09), 1.63, Gifu 2.83 (4.79), 2.23; Fukui 1.05 (2.34), 1.18; Kyoto 1.31 (2.95), 1.33; Hyogo 1.02 (2.69), 0.88; Wakayama 1.33 (3.80), 1.70; Shimane 0.83 (2.51), 0.66; Yamaguchi 1.74 (2.82), 1.76; Kochi 0.50 (2.69), 0.74 and Okinawa 1.91 (2.75), 1.22. This is the first large-scale study of current PBDE levels in breast milk in Japan.     

Ethyl mercury induces Ca2+ uptake through the P2×7 receptor in a mouse cerebellar microglia cell line

Many observations are reported that organic mercury compounds are involved in increasing intracellular Ca²⁺ levels. However, the issue of which substances on the cell membrane participate in the Ca²⁺ uptake that is induced by ethyl mercury is unclear. The findings of this study suggest that the P2X receptor participates in this process. The uptake of Ca²⁺ by C8-B4 cells was induced in the presence of ethyl mercury. Ca channels in the cell membrane were not affected in this process. In contrast, pretreatment with suramin, an antagonist of the P2X receptor, inhibited the Ca²⁺ uptake induced by ethyl mercury, and also brilliant blue G, a nonselective antagonist of P2×4, P2×5, and P2×7 receptors. In addition, A438079 and A740003, selective antagonists of P2×7 receptor, reduced Ca²⁺ uptake, while 5-BDBD, a selective antagonist of P2×4 receptor, did not. Furthermore, the mRNAs of both the P2×4 and P2×7 receptors were expressed in the presence of ethyl mercury, but the P2×5 receptor mRNA was not. These findings suggest that ethyl mercury may induce Ca²⁺ uptake through the P2×7 receptor of the cell membrane.     

Scenarios for reducing copper smelting-related atmospheric mercury emissions through copper recycling and mercury removal technologies in major countries

Journal of Material Cycles and Waste Management - Smelting of copper, a crucially important resource, releases small amounts of mercury into the atmosphere, thereby endangering people and the...