Dominant Factors of Major and Minor Components and Formation of Hydroxyalkanesulfonate in Urban Dew-Water

Dew-water was collected from January 1999 to February 2000 in Yokohama, Japan and analyzed for not only soluble major components but also insoluble or trace components. The pH of dew-water ranged from 5.36 to 6.71 and volume-weighted average pH was 5.81. In dew-water, Si, Al, Fe, Cl, and Na were abundant and they were confirmed to be transported from natural sources, sea and soil dust. The concentrations of Si, Al, Fe, and Ti contained in coarse mode aerosol were several times higher in dew-water than those in rain-water, while the concentrations of V and Pb contained in fine mode aerosol were about the same level to each other. Besides these elements derived from aerosol, the elements derived from gaseous species are also major components in dew-water. The high concentration of weak acid is one of the significant characteristics of dew-water. Bisulfite ion in dew-water is the important species as the precursor of the sulfate ion but it is stable by forming hydroxyalkanesulfonate (HASA). The HASA concentrations were evaluated by using concentrations of total S(IV) and aldehydes and hydroxymethanesulfonate (HMSA) was shown to be the dominant species in S(IV).     

Source Identification of Rural Precipitation Chemistry in Japan

Precipitation chemistry was discussed from the viewpoint of potential sources for four rural sites where wet-only daily-basis measurement data sets were available during the period from April 1996 to March 1997 in Japan. Annual volume-weighted mean concentrations of nss-SO₄ ^2? and NO₃ ^? ranged from 18.0 to 34.6 µeq L^?1, and from 9.3 to 23.1 µeq L^?1, respectively. The degree of neutralization of input acidity in terms of the concentration ratio, [H⁺] / ([nss-SO₄ ^2?] + [NO₃ ^?]), ranged from 0.46 to 0.63. This suggests that about half of the input acidity due to H₂SO₄ and HNO₃ was neutralized by NH₄ ⁺ and nss-Ca²⁺ to produce the pH values of 4.46 to 4.82 for these sites. Maximum likelihood factor analysis was then performed on the logarithmically transformed daily wet deposition of major ions. Two factors successfully explained a total of about 80% of the variance in the data for each site. Interpreting varimax rotated factor loadings, we could identify two source types: (1) acid source with large loadings on ln(H⁺), ln(nss-SO₄ ^2?), ln(NO₃ ^?) and ln(NH₄ ⁺), (2) sea-salt source with large loadings on ln(Na⁺), ln(Cl^?), ln(Mg²⁺) and ln(K⁺). The rural wet deposition over Japan appears to have a similar structure in terms of the kinds of sources and their relative location.     

Vitamin C requirement of kuruma shrimp postlarvae, Marsupenaeus japonicus (Bate), using l-ascorbyl-2-monophosphate-Na/Ca

l ‐ascorbyl‐2‐monophosphate‐Na/Ca (AMP‐Na/Ca) was used as a vitamin C source to investigate the ascorbic acid (AsA) requirements on growth performance and stress resistance of the post‐larval kuruma shrimp, Marsupenaeus japonicus. Purified carrageenan‐microbound diets with six levels of AMP‐Na/Ca, AsA equivalent to 0, 20, 56, 87, 759 and 1697 mg kg^?1 diet were fed to triplicate groups of M. japonicus (mean initial weight 16±0.3 mg) for 30 days. The diets with AsA 0, 20 and 56 mg kg^?1 showed high cumulative mortality after 10 days of feeding. After the 30‐day trial, the shrimp fed these diets had significantly lower survival and weight gain (WG, %) than those fed the 87, 759 and 1697 mg AsA kg^?1 diets. Specific growth rate and individual dry weight showed the same pattern as WG (%). There were no significant differences in growth performance among the groups fed the AsA levels at 87, 759 and 1697 mg kg^?1 at the termination of feeding trial. Broken‐line regression analysis indicated that 91.8 mg AsA kg^?1 in the diet was the optimum for post‐larval shrimp. On the other hand, dietary level of more than 800 mg AsA kg^?1 was needed to ensure high resistance to stressful conditions such as osmotic and formalin stressors.     

Changes of proximate compositions and myoglobin content in the dorsal ordinary muscles of the cultured Pacific bluefin tuna <Emphasis Type="Italic">Thunnus orientalis</Emphasis> with growth

ABSTRACT:   Using the dorsal ordinary muscle (DOM) of cultured Pacific bluefin tuna (body length [BL]: 47.5–81.8 cm, body weight [BW]: 2.1–13.5 kg, n  = 15), the changes of proximate compositions and myoglobin (Mb) content with growth were investigated. There was a positive correlation ( r  = 0.9832, P  < 0.05) of BL and BW in cultured tuna. The protein contents of the DOM of cultured tuna decreased ( P  < 0.05) and the lipid contents had a tendency to increase (not significantly) with growth. The meat color changed from pink to red with growth. In addition, the Mb contents of the DOM of cultured tuna increased ( P  < 0.05) from 1.0 mg/g (minimum BW fish) to 3.8 mg/g (maximum BW fish) with growth. These results indicate that the increase of the Mb content in the DOM of cultured tuna is not caused by the restriction of exercise and overfeeding between 2.1 kg and 13.5 kg of BW.     

Influence of different dietary amino acid patterns on growth and body composition of juvenile Japanese flounder, Paralichthys olivaceus

A feeding trial using five semi-purified diets (50% crude protein) was conducted to investigate the effects of different dietary amino acid patterns on growth and body composition of juvenile Japanese flounder. The control diet contained casein and gelatin as intact protein sources and four other diets contained 30% casein–gelatin (2:1, w/w) and 20% crystalline amino acids (CAA). CAA were added to the diets to simulate the amino acid pattern found in red sea bream egg protein (REP), Japanese flounder larvae whole body protein (FLP), Japanese flounder juvenile whole body protein (FJP), and brown fish meal protein (BFP), respectively. The test diets were fed to triplicate groups of juveniles (2.75±0.05 g) twice a day for 40 days to evaluate weight gain, survival, feed conversion efficiency (FCE), protein efficiency ratio (PER), and apparent protein utilization (APU). The apparent retention of total dietary amino acids in the whole body and A/E ratios of the whole body were also evaluated. The highest weight gain was observed in fish fed the diet containing the dietary amino acid pattern of BFP followed by fish fed the control, FJP, FLP and the REP diets. Percent survival, FCE, PER and APU were also significantly (P<0.05) affected by the amino acid pattern in the diets, indicating the highest value in fish fed the BFP diet. Except for a few amino acids, the amino acid composition of the whole body did not show marked differences with different dietary amino acid pattern. Results suggest that BFP could be more suitable as a reference amino acid pattern in the diet of juvenile Japanese flounder compared to the amino acid pattern of FLP, FJP or REP.     

Comparison of apparent digestibility coefficient among replicates and different stocking density in red sea bream <Emphasis Type="Italic">Pagrus major</Emphasis>

Two consecutive feeding trials were conducted to know: (i) how the apparent digestibility coefficient (ADC) varies among replicates on different days and during the course of the experiment (Trial 1); and (ii) the effect of stocking density (e.g. 7.17, 5.56, and 3.92 kg fish/t water) on the ADC of nutrients and energy in red sea bream (Trial 2). In both trials, 0.5% Cr₂O₃ was used as an inert marker. In Trial 1, there were no significant differences in ADC within the replicates although the values on different days varied significantly during the second week. The ADC of all parameters in the third and fourth weeks was significantly higher than in the second week (P<0.05). Although statistically insignificant, the lower stocking densities (3.92 and 5.56 kg fish/t water) showed better growth performance and superior ADC of protein, lipid, and energy than the higher stocking density in Trial 2. The results indicated that it may be better to acclimate fish to the diet for at least three weeks to obtain more reliable data by using a single tank for each treatment for digestibility experiments. Results also indicated that growth and digestibility performance can be stimulated by controlling stocking density.     

An H5N1 highly pathogenic avian influenza virus that invaded Japan through waterfowl migration

In 2010, an H5N1 highly pathogenic avian influenza virus (HPAIV) was isolated from feces of apparently healthy ducks migrating southward in Hokkaido, the northernmost prefecture of Japan. The H5N1 HPAIVs were subsequently detected in domestic and wild birds at multiple sites corresponding to the flyway of the waterfowl having stopovers in the Japanese archipelago. The Hokkaido isolate was genetically nearly identical to H5N1 HPAIVs isolated from swans in the spring of 2009 and 2010 in Mongolia, but less pathogenic in experimentally infected ducks than the 2009 Mongolian isolate. These findings suggest that H5N1 HPAIVs with relatively mild pathogenicity might be selected and harbored in the waterfowl population during the 2009-2010 migration seasons. Our data provide "early warning" signals for preparedness against the unprecedented situation in which the waterfowl reservoirs serve as perpetual sources and disseminators of HPAIVs.     

Trehalose may prevent postsurgical adhesions in a rabbit model of hysterotomy

The adhesion-preventing effect of trehalose in visceral organs was evaluated in a rabbit model. All rabbits underwent a hysterotomy, during which mild abrasion and desiccation was induced on the surfaces of visceral organs. In the control group, the intestines were kept dry during hysterotomy. In the saline and trehalose groups, saline solution and 7% trehalose solution, respectively, were sprayed on the organ surfaces. Adhesion formation on organ surfaces on which abrasion and desiccation were induced declined significantly in the trehalose group compared with the other groups. In contrast, at the hysterotomy site, there was no significant difference in adhesions between groups, suggesting that trehalose prevents adhesions in organs that have developed minor inflammation by abrasion and desiccation.