Physiological responses during stress and subsequent recovery at different salinities in adult pejerrey Odontesthes bonariensis

Mortality and physiological responses (plasma cortisol, glucose, osmolality, ions Na⁺ and Cl⁻ and hematocrit values) were examined in adult pejerrey Odontesthes bonariensis subjected to transport or crowding and subsequent recovery for 1 week at 0, 5 and 20 ppt NaCl. Two experiments were conducted using fish from different hatcheries; the following responses were consistent for both stocks. Mortality was observed only during post-stress recovery at 0 and 20 ppt NaCl but not at 5 ppt. During recovery, blood cortisol and glucose were generally higher, whereas osmolality and blood electrolytes (Na⁺ and Cl⁻) were lower at 0 ppt than at the other salinities. A salinity of 5 ppt NaCl could not prevent the rise in cortisol and glucose levels caused by the stress of transport, but during recovery, it prevented further increases in these features and/or accelerated their return to basal levels. This salinity also helped maintain stable blood electrolyte levels. During recovery at 20 ppt NaCl, osmolality and blood ions increased, whereas plasma cortisol and glucose generally decreased. Hematocrit values were lower at 20 ppt than at the other salinities. These results suggest that freshwater is not an adequate medium for post-stress recovery and that the presence of NaCl in the water either decreases the secretion of cortisol or promotes its clearance in O. bonariensis.     

Fate of pesticides during beer brewing

The fates of more than 300 pesticide residues were investigated in the course of beer brewing. Ground malt artificially contaminated with pesticides was brewed via steps such as mashing, boiling, and fermentation. Analytical samples were taken from wort, spent grain, and beer produced at certain key points in the brewing process. The samples were extracted and purified with the QuEChERS (Quick Easy Cheap Effective Rugged and Safe) method and were then analyzed by LC-MS/MS using a multiresidue method. In the results, a majority of pesticides showed a reduction in the unhopped wort and were adsorbed onto the spent grain after mashing. In addition, some pesticides diminished during the boiling and fermentation. This suggests that the reduction was caused mainly by adsorption, pyrolysis, and hydrolysis. After the entire process of brewing, the risks of contaminating beer with pesticides were reduced remarkably, and only a few pesticides remained without being removed or resolved.     

One-solvent extraction of astaxanthin from lactic acid fermented shrimp wastes

Free astaxanthin one-solvent extractions with ethanol, acetone, and liquid 1,1,1,2-tetrafluoroethane from raw and lactic acid fermented (ensilaged) shrimp residues were investigated. The total carotenoid recovery from ensilaged shrimp wastes was higher than that from non-ensilaged ones as assessed by HPLC analyses. Acetone gave the highest extraction yields of free astaxanthin with up to 115 microg/g of material. Moreover, liquid tetrafluoroethane is reported for the first time in a successful one-solvent extraction of carotenoids from shrimp.     

Monitoring of xylem embolism and dysfunction by the acoustic emission technique in Pinus thunbergii inoculated with the pine wood nematode Bursaphelenchus xylophilus

Xylem dysfunction progresses rapidly in Pinus thunbergii infected with pine wilt disease. The present report deals with the timing and process of the extensive dehydration of tracheids by embolism and the subsequent desiccation of the xylem with disease development. An ultrasonic acoustic emission (AE) technique was used to detect embolisms in the xylem of pine trunks. In most of the P. thunbergii saplings inoculated with the pathogen Bursaphelenchus xylophilus, the AE frequency suddenly increased in the second week after inoculation. The high-frequency AE continued for about 3 days and into the nights. Harvesting of specimens at this time revealed that white air-filled patches, representing the dehydrated and dysfunctional areas, had just emerged in the sapwood. The AE events in the night must be due to something other than embolisms in healthy trees. Frequent embolism of tracheids, which was suggested by the elevation of the AE frequency, might occur due to the decrease in the tensile strength of xylem sap. This hypothesis is supported by previously reported data. Host cells that had reacted to infection with B. xylophilus produce and release chemicals which can lower the surface tension of xylem sap. During the second increase of AEs, most of which occurred in the third week, xylem desiccation and needle yellowing progressed. Needle fading then became distinct, and the tree was close to death when the AE frequency dropped during the fourth week. By monitoring the AE, the first physiological abnormality that took place very early after infection was detected.     

Evaporative light-scattering analysis of sulforaphane in broccoli samples: Quality of broccoli products regarding sulforaphane contents

Broccoli sulforaphane has received attention as a possible anticarcinogen. Sulforaphane analysis is difficult due to the lack of a chromophore for spectrometric detection. Hence, we developed a method for determining sulforaphane by using high-performance liquid chromatography (HPLC) coupled with an evaporative light-scattering detector (ELSD). Sulforaphane was extracted from acid-hydrolyzed broccoli samples, followed by solid-phase extraction and reversed-phase HPLC. Sulforaphane was detected by ELSD and concurrently identified by electrospray ionization time-of-flight mass spectrometry. The recovery of sulforaphane from broccoli samples was above 95%. The detection limit was 0.5 mug. The present method was sensitive enough to determine sulforaphane in mature broccoli, broccoli sprouts, and commercial broccoli products. Sulforaphane concentration in broccoli sprout (1153 mg/100 g dry weight) was about 10 times higher than that of mature broccoli (44-171 mg/100 g dry weight). Therefore, the broccoli sprout is recommended as a source of sulforaphane-rich products. In contrast, we found that sulforaphane could not be detected in most of broccoli products, suggesting present commercial broccoli products having low quality.     

Mineralogy and petrology of comet 81P/Wild 2 nucleus samples

The bulk of the comet 81P/Wild 2 (hereafter Wild 2) samples returned to Earth by the Stardust spacecraft appear to be weakly constructed mixtures of nanometer-scale grains, with occasional much larger (over 1 micrometer) ferromagnesian silicates, Fe-Ni sulfides, Fe-Ni metal, and accessory phases. The very wide range of olivine and low-Ca pyroxene compositions in comet Wild 2 requires a wide range of formation conditions, probably reflecting very different formation locations in the protoplanetary disk. The restricted compositional ranges of Fe-Ni sulfides, the wide range for silicates, and the absence of hydrous phases indicate that comet Wild 2 experienced little or no aqueous alteration. Less abundant Wild 2 materials include a refractory particle, whose presence appears to require radial transport in the early protoplanetary disk.     

Conversion of soil particle size distribution and texture classification from ISSS system to FAO/USDA system in Japanese paddy soils

ABSTRACT

The conversion between the two different systems, ISSS and FAO/USDA, of particle size distribution and soil texture classification is useful to characterize soil physical properties and usage of each published. The objective of this study is to test some functions that have been published for conversion from ISSS to FAO/USDA system for Japanese paddy soils and to select the best method. We tested the topsoils of 267 Japanese paddy fields using the log-linear method, log-normal method, multiple regression method, Skaggs et al.’s method, and Minasny and McBratney’s method. The least AIC was obtained using multiple regression method, and the equation derived was given as follows:

si_FAO/USDA = 1.305si_ISSS + 0.396fs_ISSS?0.100cs_ISSS ? 12.323

where si, fs, and cs are the percentage of silt, fine sand, and coarse sand respectively; ISSS and FAO/USDA is the fractionation system; and its RMSE was 3.1%. For the case that only the total sand content (s) is available instead of fine sand and coarse sand, the following equation was obtained:

si_FAO/USDA = 0.314si_ISSS + 1.533s_ISSS ? 20.903 (RMSE = 3.7%)

Among the non-empirical methods, the best estimation method was Skaggs et al.’s method, and its RMSE was 3.3%. The soil texture classification by FAO/USDA system using estimated particle size fractions by the above equation can be classified to correct categories. The accuracy ratio of the classification was 93-97%.     

Effect of the long-term application of organic matter on soil carbon accumulation and GHG emissions from a rice paddy field in a cool-temperate region,Japan-II. Effect of different compost applications-

ABSTRACT

The influence of long-term application of different types of compost on rice grain yield, CH₄ and N₂O emissions, and soil carbon storage (0 ? 30 cm) in rice paddy fields was clarified. Two sets of paddy fields applied with rice straw compost or livestock manure compost mainly derived from cattle were used in this study. Each set comprised long-term application (LT) and corresponding control (CT) plots. The application rates for rice straw compost (42 years) and livestock manure compost (41 years in total with different application rates) were 20 Mg fresh weight ha^–1. Soil carbon storage increased by 33% and 37% with long-term application of rice straw compost and livestock manure compost, respectively. The soil carbon sequestration rate by the organic matter application was 23% higher with the livestock manure compost than with the rice straw compost. The rice grain yield in the LT plot was significantly higher than that in the corresponding CT plot with both types of compost. Although the difference was not significant in the rice straw compost, cumulative CH₄ emissions increased with long-term application of both composts. Increase rate of CH₄ emission with long-term application was higher in the livestock manure compost (99%) than that in the rice straw compost (26%). In both composts, the long-term application did not increase N₂O emission significantly. As with the rice straw compost, the increase in CH₄ emission with the long-term application of livestock manure compost exceeded the soil carbon sequestration rate, and the change in the net greenhouse gas (GHG) balance calculated by the difference between them was positive, indicating a net increase in the GHG emissions. The increase in CH₄ and net GHG emissions owing to the long-term application of the livestock manure compost could be higher than that of the rice straw compost owing to the amount of applied carbon, the quality of compost and the soil carbon accumulation. The possibility that carbon sequestration in the subsoil differs depending on the type of composts suggests the importance of including subsoil in the evaluation of soil carbon sequestration by long-term application of organic matter.     

Changes in the respiratory quinone profile of a soil treated with pesticides

The effects of the pesticides fenitrothion, chlorothalonil, chloropicrin, linuron, and simazine on the structure of microbial communities in a Nagoya University Farm soil (Typic Palehumult) were assessed for 28 days by monitoring changes in respiratory quinone profiles. Pesticides were applied to the soil at 10 times the recommended rates. Fenitrothion, linuron, and simazine did not significantly affect the total amount of quinones (an indicator of microbial biomass), the diversity of the quinones (an indicator of taxonomic diversity of the microbial community), or the composition of the quinone species (an indicator of community structure). Chlorothalonil decreased the diversity of quinones immediately after application, but no significant effect was observed after 3 days of incubation. The amount and composition of the quinones were not affected by chlorothalonil application. Application of chloropicrin decreased the amount and diversity of the quinones for 28 days. A continuous change in the structure of the microbial community in the chloropicrin-treated soil was documented by the change in the dominant quinone species. No change was observed in the control soil. It was suggested that quinone profile analysis is a potential method to detect the effect of pesticide on a soil microbial community. Less pronounced changes in the quinone profile indicated that changes in the structure of a soil microbial community may be masked by the persistent quinones from killed microorganisms.