Hatchery-roared juvenile black sea breams are characterized by a low level of highly unsaturated fatty acids in their bodies, as compared with wild fish. To assess the effect of docosahaxaenoic acid (DHA) on lipegen...Hatchery-roared juvenile black sea breams are characterized by a low level of highly unsaturated fatty acids in their bodies, as compared with wild fish. To assess the effect of docosahaxaenoic acid (DHA) on lipegenic and lipelysis enzymes, one-year fish were roared on a casein-based purified diet and a DHA fortified diet ( 1.5% DHA ethyl ester/kg diet) for 60 d, followed with a period of 55 d for starvation. Dietary DHA was effectively incorporated into the fish body. Fortification of DHA depressed activities of glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase as lipogenic enzymes in the hepatopancroas and intraperitoneal fat body. Carnitine palmitoyltransferase as lipolysis enzyme in the hepatopancreas was active in the DHA fortified fish. Starvation after feeding experiment induced increased carnitine palmitoyltransferase activity in both control and DHA fortified fish and the activity remained higher in the DHA fortified fish, while the monoenes were selectively consumed prior to highly unsaturated fatty acids. These results indicated that dietary DHA depressed lipogenesis and activated lipolysis.展开更多
This study investigated the linkages between river water quality and land use in river catchments in Yama- guchi Prefecture, the western Japan, in order to examine the effect of land use changes of both entire catchme...This study investigated the linkages between river water quality and land use in river catchments in Yama- guchi Prefecture, the western Japan, in order to examine the effect of land use changes of both entire catchment and buffer zone on river water quality. Dissolved Oxygen (DO), pH, Biological Oxygen Demand (BOD), Suspended Solids (SS), Escherichia coli, Total Nitrogen (TN) and Total Phosphorus (TP) were considered as river water quality indica- tors. Satellite images were applied to generating the land use map. Multiple regression model was applied to linking the changes in the river water quality with the land uses in both entire catchment area and buffer zone. The results in- dicate that the integrative application of land use data from the entire catchment and the buffer zone could give rise to more robust model to predict the concentrations of Suspended Solids (r2=0.88) and Total Nitrogen (r2=0.90), rather than models which separately considered land use data in catchment and buffer zone.展开更多
PCR and DNA sequencing were used to screen and characterize integrons and resistance genes in Gram-negative bacteria isolated from seafood products in Japan.A total of 215 Gram-negative bacteria were isolated from loc...PCR and DNA sequencing were used to screen and characterize integrons and resistance genes in Gram-negative bacteria isolated from seafood products in Japan.A total of 215 Gram-negative bacteria were isolated from local and imported seafood samples collected from retail markets in Hiroshima Prefecture.Class 1 integrons containing gene cassettes encoding resistance to trimethoprim展开更多
This study deals with the biogeography of Antarctic microflora (Antarctica acts as best model to study microbial biogeography) such as cyanobacteria and selected halophiles with special emphasis on Halomonas variabi...This study deals with the biogeography of Antarctic microflora (Antarctica acts as best model to study microbial biogeography) such as cyanobacteria and selected halophiles with special emphasis on Halomonas variabilis and Bacillus licheniformis.Halophiles are known to be resistant not only to salt stress,but also to extreme temperature,pressure,and aridity and they are capable of surviving in harsh environments such as polar regions,deep-sea habitats,and deserts.Many microbes are known to be resistant to hostile environmental conditions,and are capable of surviving in harsh environments.Our group has isolated 444 strains belonging to 28 genera of halophiles from various environments around the world.The 16S rRNA gene sequences revealed that many of the isolated strains from geographically distant habitats having different environmental conditions,were closely related to each other,with some strains possessing 100% identical sequences.Organisms possessing survival mechanism such as spore formation are usually ubiquitous.The genus Halomonas is represented by potentially endemic strains and the ubiquitous H.variabilis,while spore-forming B.licheniformis showed cosmopolitan distribution.One potentially endemic (moderate endemicity that is regional and/or continental distribution) strain was reported from Syowa station,East Antarctica,and Mario Zucchelli station,West Antarctica,which are geographically separated by 3000 km.Moreover,15 strains having 100% similarity with B.licheniformis were considered cosmopolitans.The results of this work provide support for the middle-ground model that some microbes have moderate endemicity and others have cosmopolitan distribution.These results will contribute to a greater understanding of microbial biogeography with special emphasis on Antarctica.展开更多
The efficacy of grass carp Ctenopharyngodon idella (Cyprinidae) and weevils Neochetina spp. (Curculionidae) to control the aquatic weed, water hyacinth, is investigated in a square net cage (happas) setting at a...The efficacy of grass carp Ctenopharyngodon idella (Cyprinidae) and weevils Neochetina spp. (Curculionidae) to control the aquatic weed, water hyacinth, is investigated in a square net cage (happas) setting at a farm in Cuddalore District, South India. This novel combination of insects and fish is found to be superior to individual treatments for controlling the weed growth within ll0 d. The biomass of the weed, number of plants, percentage of flowered plants and chlorophyll contents were studied. The weed biomass is reduced from 5 kg (day 1) to 0.33 kg (day 110) when exposed to grass carp and weevils. The number of plants is reduced to 0.75 in grass carp and weevil exposed happas, while it is 741.5 in the control. The mean number of leaves per plant is also reduced. In addition, the chlorophyll a and b are significantly reduced in happas exposed to the combination of fish and insects when compared to the other treatments. Based on the results of this study, we consider the combined use of grass carp and weevils to be more efficient and sustainable for managing water hyacinths than the use of these organisms individually.展开更多
The Gulf of Kachchh in western India, with its arid climate, large semi-diurnal tidal amplitudes, negative water balance and near-pristine water quality, is being extensively developed as oil importing bases for econo...The Gulf of Kachchh in western India, with its arid climate, large semi-diurnal tidal amplitudes, negative water balance and near-pristine water quality, is being extensively developed as oil importing bases for economic reasons in connection with its proximity to the oil exporting countries of the Middle East. Besides, new coral rubbings were sighted in Jakhau, north-western Gulf of Kachchh. Dredging in Mandvi of the north Gulf covering 3.5 km2 revealed a similar assortment of live corals with their associated flora and fauna. These pioneering observations demonstrate that there exist live corals of young polyps-colony of Favia sp. belonging to the family Faviidae in the north-western Gulf of Kachchh. The environmental parameters there were carefully recorded as: surface water temperature (℃) varying from 29 to 31.8, salinity (ppt), pH, dissolved oxygen (mgL-1) and total suspended solids (mgL-1) in the ranges of 37- 43.5, 7.7- 8.45, 5.4 - 6.8 and 11- 31, respectively.展开更多
Blooms of the scyphozoan jellyfish <i><span style="font-family:Verdana;">Aurelia aurita</span></i><span style="font-family:Verdana;"> are greatly regulated by the surv...Blooms of the scyphozoan jellyfish <i><span style="font-family:Verdana;">Aurelia aurita</span></i><span style="font-family:Verdana;"> are greatly regulated by the survival rate of planktonic ephyrae. The ecophysiology of ephyrae is poorly studied compared with polyps and medusae. As extremely strong starvation resistance and recovery capability of </span><i><span style="font-family:Verdana;">A. aurita</span></i><span style="font-family:Verdana;"> ephyrae may due to its low metabolic rate as well as starvation may reduce the swimming ability of ephyrae which may lead to the higher predation loss, the effects of temperature and starvation on their respiration and pulsation rates were examined. In this study, ephyrae under different starvation conditions were measured by a fluorescence-based DO meter after 72 h incubation. And the pulsation rates were measured at every 10-d interval in 1-liter plastic bottle by a hand-held counter. The results showed that the mean respiration rates of newly released ephyrae were 0.24, 0.24 and 0.19 μl O</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> ephyra</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> d</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> at 15°C, 12°C and 9°C, respectively, and the rates tended to decrease with increasing starvation duration. Carbon weight-specific respiration rates did not change significantly with starvation duration. The dry weight-specific respiration rates of newly released </span><i><span style="font-family:Verdana;">A. aurita</span></i><span style="font-family:Verdana;"> ephyrae (</span><i><span style="font-family:Verdana;">i.e.</span></i><span style="font-family:Verdana;">, 11.7</span><span style="font-size:10pt;font-family:Verdana;">-</span><span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;">14.6 μl O</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> mg DW</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> d</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) were nearly one order of magnitude lower than the rates for planktonic larvae of other taxa (e.g., molluscs, crustaceans and fish). The maximum pulsation rate taken by </span><i><span style="font-family:Verdana;">A. aurita</span></i><span style="font-family:Verdana;"> ephyrae was 49.2 beats min</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">, which represents the maximum swimming velocity to be 8.87 cm·min</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">. The pulsation rates were not affected by temperature over the range between 9°C and 15°C. However, they were influenced by starvation duration. Starvation-derived decrease in pulsation together with associated body shrinkage may lead to lower encounter rate of prey and lower escaping ability from predators, which may lead to higher predation loss in the field.</span></span>展开更多
Measurement of uronic acids (URAs) which are a group of acidic sugar, would be useful for the understanding of dynamics of bacterial extracellular polymeric substances (EPS) in marine environments. However, the URA an...Measurement of uronic acids (URAs) which are a group of acidic sugar, would be useful for the understanding of dynamics of bacterial extracellular polymeric substances (EPS) in marine environments. However, the URA analysis using traditional hydrolysis method which is used for neutral sugar analysis poses serious problems in URA that is unstable under hydrolysis. We developed the methanolysis method, which deploymerizes polysaccharides while retaining quantitative information. Our method was applied to coastal seawater, and the URAs distribution was compared with that of transparent exopolymer particles (TEP) which are acidic sugar containing particles. Since the relationship of URA with TEP was relatively weak, URA-containing polysaccharides present in bacterial EPS would not participate as a structural component of TEP.展开更多
This study discusses the fusion of chlorophyll-a (Chl.a) estimates around Tachibana Bay (Nagasaki Prefecture, Japan) obtained from MODIS and GOCI satellite data. First, the equation of GOCI LCI was theoretically calcu...This study discusses the fusion of chlorophyll-a (Chl.a) estimates around Tachibana Bay (Nagasaki Prefecture, Japan) obtained from MODIS and GOCI satellite data. First, the equation of GOCI LCI was theoretically calculated on the basis of the linear combination index (LCI) method proposed by Frouin et al. (2006). Next, assuming a linear relationship between them, the MODIS LCI and GOCI LCI methods were compared by using the Rayleigh reflectance product dataset of GOCI and MODIS, collected on July 8, July 25, and July 31, 2012. The results were found to be correlated significantly. GOCI Chl.a estimates of the finally proposed method favorably agreed with the in-situ Chl.a data in Tachibana Bay.展开更多
In this study, we tested the hypotheses that 1) diabetes-induced disturbances in cardiac my-ATPase activity would be attributed to not only myosin heavy chain (MHC) isoform transitions, but also reduced amounts in MHC...In this study, we tested the hypotheses that 1) diabetes-induced disturbances in cardiac my-ATPase activity would be attributed to not only myosin heavy chain (MHC) isoform transitions, but also reduced amounts in MHC protein;and 2) if diabetes results in declines in the MHC protein content, this change would relate to oxidative damage to MHC. Diabetes was induced by a single intraperitoneal injection of streptozotocin. After 6 weeks of injection, the left ventricles were excised for mechanical and biochemical analyses. Peak twitch tension and the rate of force development in papillary muscles were decreased by 23.4% and 34.1%, respectively. A 33.5% reduction in myofibrillar ATPase activity occurred in conjunction with a 9.5% decrease in MHC protein as well as MHC isoform transitions towards a slower phenotype. The decreased MHC content was not accompanied by elevations in carbonyl groups present in MHC. Whole muscle analyses indicated that the contents of malondialdehyde and reduced glutathione were elevated. These results suggest that decreases in the MHC content may be associated, at least in part, with a diabetes-related inactivation of cardiac my-ATPase and may not be due to accumulation of oxidative damage to protein.展开更多
Structural characteristics of xyloglucan are constant in the pericarp cell walls of kiwifruit (Actinidia deliciosa) throughout fruit enlargement and maturation. Most of the xyioglucan (XG) persists in the cell wal...Structural characteristics of xyloglucan are constant in the pericarp cell walls of kiwifruit (Actinidia deliciosa) throughout fruit enlargement and maturation. Most of the xyioglucan (XG) persists in the cell walls of ripe kiwifruit. XG from the pericarp tissues of 36-h ethylene-treated kiwifruit was extracted as hemicellulose Ⅱ (HC-Ⅱ) with 4.28 M KOH containing 0.02% NaBH4, and purified using iodine precipitation and subsequent anion-exchange chromatography. This purifying protocol increased XG purity from 50 mol% in HC-Ⅱ fraction to 62 mol% in the purified XG powder. The molar ratio of glucose: xylose: galactose: fucose in the purified XG was 10: 6.9: 2.1: 0.3. Gel permeation chromatography indicated that purified XG had an average molecular-mass of 161 KDa, a value that exceeds the 95 KDa Mr determined for total polymeric sugars. Sugar linkage analysis confirmed the lack of fucose in the kiwifruit XG, but a small amount of arabinoxylan and low Mr glucomannan remained associated with this fraction.展开更多
The photo-Fenton reaction is a key source of the highly reactive hydroxyl radical(HOU) that is produced by the reaction of simultaneous photo-induced generation of Fe^(2+)-dissolved organic matter(DOM) with H_2...The photo-Fenton reaction is a key source of the highly reactive hydroxyl radical(HOU) that is produced by the reaction of simultaneous photo-induced generation of Fe^(2+)-dissolved organic matter(DOM) with H_2O_2 in sunlit surface waters as well as in the treatment of organic pollutants in the advanced oxidation processes(AOPs).Concentrations of both H_2O_2 and Fe^(2+)-DOM were dependent on time and total solar intensity flux,and their levels were highest in the diurnal samples collected at noon compared with the samples collected during the period before sunrise and after sunset.H_2O_2 and Fe^(2+)-DOM concentrations during monthly readings were also found higher in comparison with the diurnal samples,shortly before sunrise or after sunset.A π-electron bonding system is formed between Fe and the functional groups in DOM(Fe-DOM),through electron donation from the functional groups of DOM to an empty d-orbital of Fe.The π-electron is loosely bound and is highly susceptible to a rapid excitation upon light exposure that will provide better understanding of the formation of aqueous electrons,superoxide radical anions,H_2O_2 and finally,photo-Fenton reactions,too.Our results imply that simultaneous generation of H_2O_2 and Fe^(2+)-DOM upon sunlight exposure during the daytime is most likely to be the key photo-Fenton reaction pathway,taking place in surface waters.展开更多
This study addresses the hypothesis that stagnation of soybean yield on the farm can be improved by selection of a physiological trait favoring carbon assimilate partitioning to terminally placed pods versus genotypes...This study addresses the hypothesis that stagnation of soybean yield on the farm can be improved by selection of a physiological trait favoring carbon assimilate partitioning to terminally placed pods versus genotypes having axillary pods at close plant spacing.13C was fed to source-sink units comprising a leaf,axillary/terminal pods,and petioles at upper and lower positions of the stem axis in two soybean cultivars,namely Shakujo and Enrei,at different densities of populations.The cultivars differ significantly in architecture,Shakujo bearing a few hundreds of pods in close succession to one another in a terminally placed raceme,in contrast to Enrei having axillary racemes.Pod yield per plant was higher in Enrei than in Shakujo at low density,but Shakujo out-yielded Enrei at close spacing.Population density decreased yield per plant and altered the pattern of assimilate partitioning significantly within the plants for both varieties.At high density more assimilates moved to the upper parts at the cost of the lower parts.The terminally placed pods of Shakujo were advantaged to receive assimilates under density stress.No benefit was accrued to pod filling of Enrei,however,under this condition.展开更多
We reviewed organophosphorus pesticide use in Japan between 1982 and 2016 using data from the National Institute of Environmental Studies. Organophosphorus pesticide concentrations in river water throughout Japan were...We reviewed organophosphorus pesticide use in Japan between 1982 and 2016 using data from the National Institute of Environmental Studies. Organophosphorus pesticide concentrations in river water throughout Japan were taken from the literature, and risk assessments were performed for some organophosphorus pesticides based on risk quotients and hazard quotients. Assessments were performed for 20 common pesticides,including insecticides, fungicides, and herbicides. The amounts used decreased in the order: insecticides > herbicides > fungicides. Organophosphorus insecticide and fungicide use have decreased over the last four decades, but organophosphorus herbicide use has increased. During this period, annual organophosphorus pesticide use was the highest for chlorpyrifos(105,263 tons/year) and the lowest for glyphosate-sodium(8 tons/year). The ecotoxicological risk assessment indicated that diazinon and fenitrothion posed strong risks to the Japanese aquatic environment, and chlorpyrifos and malathion have moderate risks. None of the pesticides that were assessed posed significant risks to humans.Continued use of organophosphorus pesticides in Japan may cause strong risks to aquatic environments. These risks should be reassessed periodically.展开更多
文摘Hatchery-roared juvenile black sea breams are characterized by a low level of highly unsaturated fatty acids in their bodies, as compared with wild fish. To assess the effect of docosahaxaenoic acid (DHA) on lipegenic and lipelysis enzymes, one-year fish were roared on a casein-based purified diet and a DHA fortified diet ( 1.5% DHA ethyl ester/kg diet) for 60 d, followed with a period of 55 d for starvation. Dietary DHA was effectively incorporated into the fish body. Fortification of DHA depressed activities of glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase as lipogenic enzymes in the hepatopancroas and intraperitoneal fat body. Carnitine palmitoyltransferase as lipolysis enzyme in the hepatopancreas was active in the DHA fortified fish. Starvation after feeding experiment induced increased carnitine palmitoyltransferase activity in both control and DHA fortified fish and the activity remained higher in the DHA fortified fish, while the monoenes were selectively consumed prior to highly unsaturated fatty acids. These results indicated that dietary DHA depressed lipogenesis and activated lipolysis.
文摘This study investigated the linkages between river water quality and land use in river catchments in Yama- guchi Prefecture, the western Japan, in order to examine the effect of land use changes of both entire catchment and buffer zone on river water quality. Dissolved Oxygen (DO), pH, Biological Oxygen Demand (BOD), Suspended Solids (SS), Escherichia coli, Total Nitrogen (TN) and Total Phosphorus (TP) were considered as river water quality indica- tors. Satellite images were applied to generating the land use map. Multiple regression model was applied to linking the changes in the river water quality with the land uses in both entire catchment area and buffer zone. The results in- dicate that the integrative application of land use data from the entire catchment and the buffer zone could give rise to more robust model to predict the concentrations of Suspended Solids (r2=0.88) and Total Nitrogen (r2=0.90), rather than models which separately considered land use data in catchment and buffer zone.
基金supported by a Grant-in-Aid for Scientific Research(No.25460532 and 26.04912)to Tadashi S.from the Ministry of Education,Culture,Sports,Science,and Technology of Japan
文摘PCR and DNA sequencing were used to screen and characterize integrons and resistance genes in Gram-negative bacteria isolated from seafood products in Japan.A total of 215 Gram-negative bacteria were isolated from local and imported seafood samples collected from retail markets in Hiroshima Prefecture.Class 1 integrons containing gene cassettes encoding resistance to trimethoprim
基金partly supported by the Special Coordination Fund"Archaean Park Project:International research project on interaction between sub-vent biosphere and geo-environments"of the Ministry of Education,Culture,Sports,Science and Technology of Japanthe NIPR collaborative research program No.99(2002-2004)+2 种基金the Fund"Construct the Genetic Resource Library of Unidentifed Microbes Based on Genome Information"from the New Energy and Industrial Technology Development Organization,JapanGrants-in-Aid for Scientifc Research(11833012,14340268,and 18255005)from the Japan Society for the Promotion of Scienceand Antarctic samples from Livingston Island were collected during the Spanish program LIMNOPOLAR in the International Polar Year(IPY)2007-2008 campaign
文摘This study deals with the biogeography of Antarctic microflora (Antarctica acts as best model to study microbial biogeography) such as cyanobacteria and selected halophiles with special emphasis on Halomonas variabilis and Bacillus licheniformis.Halophiles are known to be resistant not only to salt stress,but also to extreme temperature,pressure,and aridity and they are capable of surviving in harsh environments such as polar regions,deep-sea habitats,and deserts.Many microbes are known to be resistant to hostile environmental conditions,and are capable of surviving in harsh environments.Our group has isolated 444 strains belonging to 28 genera of halophiles from various environments around the world.The 16S rRNA gene sequences revealed that many of the isolated strains from geographically distant habitats having different environmental conditions,were closely related to each other,with some strains possessing 100% identical sequences.Organisms possessing survival mechanism such as spore formation are usually ubiquitous.The genus Halomonas is represented by potentially endemic strains and the ubiquitous H.variabilis,while spore-forming B.licheniformis showed cosmopolitan distribution.One potentially endemic (moderate endemicity that is regional and/or continental distribution) strain was reported from Syowa station,East Antarctica,and Mario Zucchelli station,West Antarctica,which are geographically separated by 3000 km.Moreover,15 strains having 100% similarity with B.licheniformis were considered cosmopolitans.The results of this work provide support for the middle-ground model that some microbes have moderate endemicity and others have cosmopolitan distribution.These results will contribute to a greater understanding of microbial biogeography with special emphasis on Antarctica.
基金Supported by the Chinese Academy of Sciences Research Fellowship for International Young Researchers to M.Rajkumar hosted by J.SUNthe Knowledge Innovation Project of the Chinese Academy of Sciences (Nos.KZCX2-YW-QN-205,KZCX2-YW-213-2) to J.SUN
文摘The efficacy of grass carp Ctenopharyngodon idella (Cyprinidae) and weevils Neochetina spp. (Curculionidae) to control the aquatic weed, water hyacinth, is investigated in a square net cage (happas) setting at a farm in Cuddalore District, South India. This novel combination of insects and fish is found to be superior to individual treatments for controlling the weed growth within ll0 d. The biomass of the weed, number of plants, percentage of flowered plants and chlorophyll contents were studied. The weed biomass is reduced from 5 kg (day 1) to 0.33 kg (day 110) when exposed to grass carp and weevils. The number of plants is reduced to 0.75 in grass carp and weevil exposed happas, while it is 741.5 in the control. The mean number of leaves per plant is also reduced. In addition, the chlorophyll a and b are significantly reduced in happas exposed to the combination of fish and insects when compared to the other treatments. Based on the results of this study, we consider the combined use of grass carp and weevils to be more efficient and sustainable for managing water hyacinths than the use of these organisms individually.
基金supported by the Chinese Academy of Sciences Research Fellowship for International Young Researchers for M. Rajkumarthe Knowledge Innovation Project of The Chinese Academy of Sciences (KZCX2-YW-QN205, KZCX2-YW-213-2)the National High Technology Research and Development Program of China (2006AA09Z179) for Dr. Jun Sun
文摘The Gulf of Kachchh in western India, with its arid climate, large semi-diurnal tidal amplitudes, negative water balance and near-pristine water quality, is being extensively developed as oil importing bases for economic reasons in connection with its proximity to the oil exporting countries of the Middle East. Besides, new coral rubbings were sighted in Jakhau, north-western Gulf of Kachchh. Dredging in Mandvi of the north Gulf covering 3.5 km2 revealed a similar assortment of live corals with their associated flora and fauna. These pioneering observations demonstrate that there exist live corals of young polyps-colony of Favia sp. belonging to the family Faviidae in the north-western Gulf of Kachchh. The environmental parameters there were carefully recorded as: surface water temperature (℃) varying from 29 to 31.8, salinity (ppt), pH, dissolved oxygen (mgL-1) and total suspended solids (mgL-1) in the ranges of 37- 43.5, 7.7- 8.45, 5.4 - 6.8 and 11- 31, respectively.
文摘Blooms of the scyphozoan jellyfish <i><span style="font-family:Verdana;">Aurelia aurita</span></i><span style="font-family:Verdana;"> are greatly regulated by the survival rate of planktonic ephyrae. The ecophysiology of ephyrae is poorly studied compared with polyps and medusae. As extremely strong starvation resistance and recovery capability of </span><i><span style="font-family:Verdana;">A. aurita</span></i><span style="font-family:Verdana;"> ephyrae may due to its low metabolic rate as well as starvation may reduce the swimming ability of ephyrae which may lead to the higher predation loss, the effects of temperature and starvation on their respiration and pulsation rates were examined. In this study, ephyrae under different starvation conditions were measured by a fluorescence-based DO meter after 72 h incubation. And the pulsation rates were measured at every 10-d interval in 1-liter plastic bottle by a hand-held counter. The results showed that the mean respiration rates of newly released ephyrae were 0.24, 0.24 and 0.19 μl O</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> ephyra</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> d</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> at 15°C, 12°C and 9°C, respectively, and the rates tended to decrease with increasing starvation duration. Carbon weight-specific respiration rates did not change significantly with starvation duration. The dry weight-specific respiration rates of newly released </span><i><span style="font-family:Verdana;">A. aurita</span></i><span style="font-family:Verdana;"> ephyrae (</span><i><span style="font-family:Verdana;">i.e.</span></i><span style="font-family:Verdana;">, 11.7</span><span style="font-size:10pt;font-family:Verdana;">-</span><span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;">14.6 μl O</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> mg DW</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> d</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) were nearly one order of magnitude lower than the rates for planktonic larvae of other taxa (e.g., molluscs, crustaceans and fish). The maximum pulsation rate taken by </span><i><span style="font-family:Verdana;">A. aurita</span></i><span style="font-family:Verdana;"> ephyrae was 49.2 beats min</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">, which represents the maximum swimming velocity to be 8.87 cm·min</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">. The pulsation rates were not affected by temperature over the range between 9°C and 15°C. However, they were influenced by starvation duration. Starvation-derived decrease in pulsation together with associated body shrinkage may lead to lower encounter rate of prey and lower escaping ability from predators, which may lead to higher predation loss in the field.</span></span>
文摘Measurement of uronic acids (URAs) which are a group of acidic sugar, would be useful for the understanding of dynamics of bacterial extracellular polymeric substances (EPS) in marine environments. However, the URA analysis using traditional hydrolysis method which is used for neutral sugar analysis poses serious problems in URA that is unstable under hydrolysis. We developed the methanolysis method, which deploymerizes polysaccharides while retaining quantitative information. Our method was applied to coastal seawater, and the URAs distribution was compared with that of transparent exopolymer particles (TEP) which are acidic sugar containing particles. Since the relationship of URA with TEP was relatively weak, URA-containing polysaccharides present in bacterial EPS would not participate as a structural component of TEP.
文摘This study discusses the fusion of chlorophyll-a (Chl.a) estimates around Tachibana Bay (Nagasaki Prefecture, Japan) obtained from MODIS and GOCI satellite data. First, the equation of GOCI LCI was theoretically calculated on the basis of the linear combination index (LCI) method proposed by Frouin et al. (2006). Next, assuming a linear relationship between them, the MODIS LCI and GOCI LCI methods were compared by using the Rayleigh reflectance product dataset of GOCI and MODIS, collected on July 8, July 25, and July 31, 2012. The results were found to be correlated significantly. GOCI Chl.a estimates of the finally proposed method favorably agreed with the in-situ Chl.a data in Tachibana Bay.
文摘In this study, we tested the hypotheses that 1) diabetes-induced disturbances in cardiac my-ATPase activity would be attributed to not only myosin heavy chain (MHC) isoform transitions, but also reduced amounts in MHC protein;and 2) if diabetes results in declines in the MHC protein content, this change would relate to oxidative damage to MHC. Diabetes was induced by a single intraperitoneal injection of streptozotocin. After 6 weeks of injection, the left ventricles were excised for mechanical and biochemical analyses. Peak twitch tension and the rate of force development in papillary muscles were decreased by 23.4% and 34.1%, respectively. A 33.5% reduction in myofibrillar ATPase activity occurred in conjunction with a 9.5% decrease in MHC protein as well as MHC isoform transitions towards a slower phenotype. The decreased MHC content was not accompanied by elevations in carbonyl groups present in MHC. Whole muscle analyses indicated that the contents of malondialdehyde and reduced glutathione were elevated. These results suggest that decreases in the MHC content may be associated, at least in part, with a diabetes-related inactivation of cardiac my-ATPase and may not be due to accumulation of oxidative damage to protein.
基金supported by the Postdoctoral Fellowship of Venture Business Laboratory in Hiroshima University and of the Japanese Society for Promotion of Science to Dr. XJ Li (P05190)
文摘Structural characteristics of xyloglucan are constant in the pericarp cell walls of kiwifruit (Actinidia deliciosa) throughout fruit enlargement and maturation. Most of the xyioglucan (XG) persists in the cell walls of ripe kiwifruit. XG from the pericarp tissues of 36-h ethylene-treated kiwifruit was extracted as hemicellulose Ⅱ (HC-Ⅱ) with 4.28 M KOH containing 0.02% NaBH4, and purified using iodine precipitation and subsequent anion-exchange chromatography. This purifying protocol increased XG purity from 50 mol% in HC-Ⅱ fraction to 62 mol% in the purified XG powder. The molar ratio of glucose: xylose: galactose: fucose in the purified XG was 10: 6.9: 2.1: 0.3. Gel permeation chromatography indicated that purified XG had an average molecular-mass of 161 KDa, a value that exceeds the 95 KDa Mr determined for total polymeric sugars. Sugar linkage analysis confirmed the lack of fucose in the kiwifruit XG, but a small amount of arabinoxylan and low Mr glucomannan remained associated with this fraction.
基金the Japan Society for the Promotion of Science for the financial support through a Grant-in-Aid for Scientific Research (B) (No.18310010)partly supported by the Key Construction Program of the National "985" Project,Tianjin University,China
文摘The photo-Fenton reaction is a key source of the highly reactive hydroxyl radical(HOU) that is produced by the reaction of simultaneous photo-induced generation of Fe^(2+)-dissolved organic matter(DOM) with H_2O_2 in sunlit surface waters as well as in the treatment of organic pollutants in the advanced oxidation processes(AOPs).Concentrations of both H_2O_2 and Fe^(2+)-DOM were dependent on time and total solar intensity flux,and their levels were highest in the diurnal samples collected at noon compared with the samples collected during the period before sunrise and after sunset.H_2O_2 and Fe^(2+)-DOM concentrations during monthly readings were also found higher in comparison with the diurnal samples,shortly before sunrise or after sunset.A π-electron bonding system is formed between Fe and the functional groups in DOM(Fe-DOM),through electron donation from the functional groups of DOM to an empty d-orbital of Fe.The π-electron is loosely bound and is highly susceptible to a rapid excitation upon light exposure that will provide better understanding of the formation of aqueous electrons,superoxide radical anions,H_2O_2 and finally,photo-Fenton reactions,too.Our results imply that simultaneous generation of H_2O_2 and Fe^(2+)-DOM upon sunlight exposure during the daytime is most likely to be the key photo-Fenton reaction pathway,taking place in surface waters.
文摘This study addresses the hypothesis that stagnation of soybean yield on the farm can be improved by selection of a physiological trait favoring carbon assimilate partitioning to terminally placed pods versus genotypes having axillary pods at close plant spacing.13C was fed to source-sink units comprising a leaf,axillary/terminal pods,and petioles at upper and lower positions of the stem axis in two soybean cultivars,namely Shakujo and Enrei,at different densities of populations.The cultivars differ significantly in architecture,Shakujo bearing a few hundreds of pods in close succession to one another in a terminally placed raceme,in contrast to Enrei having axillary racemes.Pod yield per plant was higher in Enrei than in Shakujo at low density,but Shakujo out-yielded Enrei at close spacing.Population density decreased yield per plant and altered the pattern of assimilate partitioning significantly within the plants for both varieties.At high density more assimilates moved to the upper parts at the cost of the lower parts.The terminally placed pods of Shakujo were advantaged to receive assimilates under density stress.No benefit was accrued to pod filling of Enrei,however,under this condition.
基金The Japan Society for the Promotion of Science(JSPS)supported by JSPS KAKENHI grant number16KT0149,Japan
文摘We reviewed organophosphorus pesticide use in Japan between 1982 and 2016 using data from the National Institute of Environmental Studies. Organophosphorus pesticide concentrations in river water throughout Japan were taken from the literature, and risk assessments were performed for some organophosphorus pesticides based on risk quotients and hazard quotients. Assessments were performed for 20 common pesticides,including insecticides, fungicides, and herbicides. The amounts used decreased in the order: insecticides > herbicides > fungicides. Organophosphorus insecticide and fungicide use have decreased over the last four decades, but organophosphorus herbicide use has increased. During this period, annual organophosphorus pesticide use was the highest for chlorpyrifos(105,263 tons/year) and the lowest for glyphosate-sodium(8 tons/year). The ecotoxicological risk assessment indicated that diazinon and fenitrothion posed strong risks to the Japanese aquatic environment, and chlorpyrifos and malathion have moderate risks. None of the pesticides that were assessed posed significant risks to humans.Continued use of organophosphorus pesticides in Japan may cause strong risks to aquatic environments. These risks should be reassessed periodically.