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11.
Rates of oxygen consumption, ammonia excretion and phosphate excretion were measured on a hydromedusae (Aglantha digitale), pteropods (Limacia helicina, Clione limacina), copepods (Calanus finmarchicus, C. glacialis, C. hyperboreus, Metridia longa), an amphipod (Parathemisto libellula), a euphausiid (Thysanoessa inermis) and a chaetognath (Sagitta elegans), all of which were dominant species in the Barents Sea during early summer 1987. Water and ash contents and elemental composition (C and N) were also analysed on the specimens used in these metabolic experiments. Between species variations were 67.8% to 94.7% of wet weight in water content, 6.4% to 56.5% of dry weight in ash content, 16.7% to 61.0% of dry weight in carbon content, and 4.3% to 11.2% of dry weight in nitrogen content. Oxygen consumption rates ranged from 0.33 to 13.8 l O2 individual-1 h-1, ammonia excretion rates, from 0.0072 to 0.885 gN individual-1 h-1 and phosphate excretion rates, from 0.0036 to 0.33 g P individual-1 h-1. In general, higher rates were associated with larger species, but considerable differences were also seen between species. The ratios between the rates (O : N, N : P, O : P) exhibited a wide species-specific variation, indicating differences in dominant metabolic substrates. Typical protein oriented metabolism was identified only in S. elegans. From the results of metabolic rate measurements and elemental analyses, daily losses of body carbon and nitrogen were estimated to be 0.50 to 4.15% and 0.084 to 1.87%, respectively, showing faster turnover rates of carbon than that of nitrogen. Comparison of daily loss of body carbon of the Barents Sea zooplankton with that of the Antarctic zooplankton indicated reduced rates of the former (63% on average). 相似文献
12.
Kei Asada Koki Toyota Taku Nishimura Jun-Ichi Ikeda Kaneaki Hori 《Journal of environmental science and health. Part. B》2013,48(4):285-292
Applying manure compost not only results in zinc accumulation in the soil but also causes an increase in zinc mobility and enhances zinc leaching. In this study, the physical and chemical characteristics of zinc, zinc profiles, and zinc balance were investigated to characterise the fate of zinc in fields where the quality and amount of pig manure compost applied have been known for 13 years. Moreover, we determined zinc fractionation in both 0.1 mol L?1HCl-soluble (mobile) and -insoluble (immobile) fractions. Adsorption of zinc in the soil was enhanced with increasing total carbon content following the application of pig manure compost. The 159.6 mg ha?1 year?1manure applied plot (triplicate) exceeded the Japanese regulatory level after only 6 years of applying pig manure compost, whereas the 53.2 mg ha?1 year?1 manure applied plot (standard) reached the regulatory level after 13 years. The zinc loads in the plots were 17.0 and 5.6 kg ha?1 year?1, respectively. However, 5.9 % and 17.2 % of the zinc loaded in the standard and the triplicate pig manure compost applied plots, respectively, were estimated to be lost from the plough layer. Based on the vertical distribution of mobile and immobile zinc content, a higher rate of applied manure compost caused an increase in the mobile zinc fraction to a depth of 40 cm. Although the adsorption capacity of zinc was enhanced following the application of pig manure compost, a greater amount of mobile zinc could move downward through the manure amended soil than through non manure-amended soil. 相似文献
13.
Population structure and life cycle of the mesopelagic ostracod Conchoecia pseudodiscophora in Toyama Bay,southern Japan Sea 总被引:1,自引:0,他引:1
The population structure and life cycle of the mesopelagic ostracod Conchoecia pseudodiscophora Rudjakov in Toyama Bay, southern Japan Sea, were investigated using a time-series of samples collected during 0 to 500 m vertical hausls with twin-type Norpac nets (0.35 and 0.10 mm mesh) over one full year (1 February 1990 to 30 January 1991). Additional samples were also collected with a single-type closing Norpac net (0.06 mm mesh) to examine the vertical distribution patterns of eggs and all instars of this species. The proportion of gravid females present indicated that reproduction of C. pseudodiscophora continues throughout the year, but peaks in April–July. Eggs and Instars I and II were distributed below 500 m, while the more advanced instars were most abundant in the 350 to 500 m stratum by both day and night. Based on the abundance peaks of each instar in the time-series samples, development times were estimated to be 2.5, 4, 3, 7 and 11 mo for Instars III, IV, V, VI, and VII, respectively. Thus, a total of 30 mo is required for newly spawned eggs to hatch and reach adulthood. Stomach-fullness indexes revealed no seasonality in the feeding activity of any instar stage, but that feeding activity was low in older instars, particularly in adult males. The present results are compared with those for a few other ostracod species, in an attempt to characterize the life cycle of C. pseudodiscophora inhabiting waters of subzero temperature in the mesopelagic zone of the Japan Sea. 相似文献
14.
Ecological and biological features of a mesopelagic ostracod,Conchoecia pseudodiscophora,in the Japan Sea 总被引:2,自引:0,他引:2
T. Ikeda 《Marine Biology》1990,107(3):453-461
The abundance and vertical distribution pattern of a halocyprid ostracod,Conchoecia pseudodiscophora, were investigated in the Japan Sea in 1985, 1987 and 1989. Vertical sampling from 500 m depth to the surface in the water around Yamato Rise revealed that this ostracod was second in dominance by number and third to fourth by biomass of the total zooplankton collected with a 0.35 mm mesh Norpac net. Horizontal net tows in Toyama Bay indicated that the major population ofC. pseudodiscophora was distributed below 250 to 300 m depth. No diel migration pattern was evident. Its contribution to total zooplankton there was 5 to 10% or more in terms of biomass. A total of five subadult instars (II to VI) and adult males and females were identified from instar analysis based on sizes and morphological characteristics of specimens collected with 0.10 mm mesh Norpac nets. Data on body length, wet weight and dry weight of each instar are presented. Carbon content of 35 to 48% of dry weight, and nitrogen content of 5.3 to 7.3% of dry weight, were recorded on fresh, freeze-dried specimens of selected instars (subadult Instars IV to VI, adult females). Water and ash contents of mixed specimens of these four instars were 76% of wet weight and 25% of dry weight, respectively. Feasibility of laboratory maintenance ofC. pseudodiscophora was tested, and it produced characteristic J shaped faecal pellets. Oxygen consumption rates of subadult instars V and VI, and adult female ranged 0.011 to 0.021µl O2 ind.–1 h–1 at 1 °C, or 2.9 to 6.1µl O2 (mg body N)–0.85 h–1 in terms of Adjusted Metabolic Rate (AMRo
2). There was no appreciable metabolic reduction inC. pseudodiscophora compared to other ostracods, despite their mesopelagic life mode. Subdominance in total zooplankton and nonreduced metabolic activity ofC. pseudodiscophora suggest that this species may be an important link in mesopelagic energy-flow and matter cycling in the Japan Sea. 相似文献
15.
Vertical distribution, life cycle, and developmental characteristics of the mesopelagic copepod Gaidius variabilis Brodsky in the Oyashio region were investigated by combining analyses of field copepodite populations with laboratory-rearing
data of egg hatching and naupliar development. Field samplings from five discrete depths between the surface and ≤2000 m were
made approximately every month for 1 year. Most populations of G. variabilis occurred between 600 and 1000 m depth. A modest degree of reversed diel vertical migration behavior and some stage-specific
depth-distribution patterns were noted. All copepodite stages were observed throughout the year, suggesting a year-round spawning
of G. variabilis. From a prominent abundance peak of Copepodite Stage 1 (C1) seen in June to August, together with development times of eggs
and nauplii obtained in laboratory-rearing experiments, the major spawning season was extrapolated to be April to June, the
phytoplankton bloom season. Tracing the peak abundance of each copepodite stage (distinguishing males and females for C4 to
C6), the generation times of males and females were deduced as 2 and 1 year, respectively. All between-stage increments in
terms of wet-, dry-, and ash-free dry weights were greatest in C3/C4, and least in C5/C6 for both males and females. The increments
in C3/C4 and C4/C5 were greater for males than for females, reflecting a longer stage duration of the males. These weights
did not increase in C5/C6 males, possibly because feeding ceased in C6 males. These results for G. variabilis are compared with those for some mesopelagic copepods previously reported from other regions.
Received: 25 October 1999 / Accepted: 20 March 2000 相似文献
16.
Global warming is a major concern for the Japanese public. However, because the influence of global environmental risks, particularly global warming, is long-term and widespread, it seems difficult for the public to recognize it as a familiar and important problem that necessitates firm action. This study attempts to determine the causal structure promoting risk-mitigating behavior with regard to global warming, using Covariance Structure Analysis (CSA) with data from a survey of a subset of the Japanese population. We model the causal structure promoting risk-mitigating behavior population. There are four main stages in the process of decision-making for and values, risk perception, mitigating behavior intention, and personal environmental policies has three stages: concerns and values, risk perceptions, ectively accelerate the public’s participation in policy decisions, by translating their risk-mitigating into practical actions. Increased knowledge through improved access should improve the interaction between the public and environmental policy-makers with regard to global warming, using CSA with data from a survey of a subset of the Japanese personal actions: concerns actions. Support for andmitigating behavior intentions. Our results suggest that improved access to information concerning the risks associated with global warming in particular, and environmental issues in general, will be sufficient to effintentions for to information in Japan. 相似文献
17.
Despite the fact that several manufacturers of service robots launched their innovations into the market, worldwide guidelines or regulations concerning the safety aspects of service robots are not yet available. However the general principles and methodologies of safety of machinery (e.g., ISO/IEC Guide 51, partly ISO14121, ISO12100) could be implemented to a certain degree. The safety of seven service robots as an emerging technology was verified by safety professionals of “NPO – the Safety Engineering Laboratory” a Non Profit Organization. NPO verified the “Critical Hazards” for each service robot mentioned by the respective manufacturers. For those cases, both the “As Low As Reasonably Practicable” principle and the “Reasonable Alternative Design” standard were applied for judging if the risk associated with the Critical Hazards were tolerable or not and if state of the art measures for reducing the risk were applied adequately. These experiences will help to establish guidelines for the safety of service robots as an emerging technology in the future. 相似文献
18.
T. Ikeda 《Marine Biology》1977,41(3):241-252
Herbivorous zooplankton species (Calanus plumchrus, Paracalanus parvus and Euphausia pacifica) and carnivorous species (Parathemisto pacifica and Pleurobrachia pileus) collected from Saanich Inlet, British Columbia, Canada, were maintained in the laboratory under fed and starved conditions. Respiration rate and excretion rates of ammonia and inorganic phosphate were measured successively on the same batch populations of each species in different feeding conditions. Respiration rate remained at a constant level or increased during the feeding experiment but decreased progressively in starved individuals. Herbivorous, but not carnivorous, species showed a rapid decrease in both excretion rates for the first few days of an experiment irrespective of feeding conditions. However, the general level of excretion rates of fed specimens was higher than that of starved ones. The O:N, N:P and O:P ratios were calculated from respiration, ammonia excretion and phosphate excretion and discussed in relation to metabolic substrates of animals during the experiment. A marked difference was shown in the O:N ratio between fed hervivores (>16) and fed carnivores (7 to 19), suggesting highly protein-oriented metabolism in the latter. One unknown factor causing variation in excretion rates is speculated to be the physiological stress on animals during sampling from the field. It is suggested that the laboratory measurement of realistic excretion rates of zooplankton is difficult owing to their large fluctuations, but this is not the case with respiration rate. 相似文献
19.
The outstanding advantage of the novel polishing technology developed by the authors is a considerable reduction in cerium oxide consumption for polishing of glass substrates. This has been realized by introducing tribo-chemical polishing method along with a technique to control the movement of abrasives using an AC electric field. In this paper, we have analyzed the characteristics of the new polishing technique from the viewpoint of slurry distribution in the polishing area under various electric field conditions using a digital image processing and its influence on polishing performance using the experimental setup consisting of high speed polishing method under AC electric field. The results confirmed the increase of slurry distribution in the polishing area under appropriate AC electric field conditions and consequently led to enhanced removal rate, which was 2.5 times higher than that of the conventional CMP (chemical mechanical polishing) method. Furthermore, in spite of enhanced removal rate the surface roughness was comparable to CMP method. 相似文献
20.
Environmental Fluid Mechanics - In this laboratory study, propagation behaviour, particle deposition patterns, and suspension characteristics of non-cohesive particle-driven gravity currents formed... 相似文献