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21.
In this study, we investigated the behavior of estrogens in the rhizosphere of white clover (Trifolium repens, clover hereafter) with two different pot tests, using soil and agar as growth media. In a pot test using agar spiked with estrogen, the estrogen concentration in the agar with clover decreased to non-detectable levels within one month, while in the agar without clover, 60% of initially added estrogen remained after one month. The half-lives of estrone (E1) and 17β -estradiol (E2) in the agar with clover were 2.4–3.8 and 13.2 d, respectively. The dissipation of E1 followed first-order rate law, while that of E2 fitted a zero-order reaction, indicating that they had different mechanisms of dissipation from agar. In the soil pot test, the behavior of E1 and E2 was not influenced by clover. An initial rapid decrease in the amount of estrogen extracted by methanol/acetic acid was followed by persistence for 1–3 months, regardless of presence of clover. Moreover, in three weeks E1 and E2 were only partly degraded by microbes extracted from the soil used in the pot test. In this study, abiotic degradation of estrogens and sorption of estrogen to soil, rather than the effects of soil microbes and clover, contributed to the initial rapid dissipation of estrogens in the soil. However, the results of the agar pot test suggested that vegetation such as clover may significantly contribute to removal of estrogens when estrogens in aqueous phase are discharged with surface runoff and preferential flow after heavy rain in agricultural fields, or when present in soils with low estrogen sorptivity.  相似文献   
22.
In the actual environment, temperatures fluctuate drastically through season or global warming and are thought to affects risk of pollutants for aquatic biota; however, there is no report about the effect of water temperature on toxicity of widely used herbicide diuron to fresh water microalgae. The present research investigated inhibitory effect of diuron on growth and photosynthetic activity of a green alga Pseudokirchneriella subcapitata at five different temperatures (10, 15, 20, 25, and 30 °C) for 144 h of exposure. As a result, effective diuron concentrations at which a 50 % decrease in algal growth occurred was increased with increasing water temperature ranging from 9.2 to 20.1 μg L–1 for 72 h and 9.4–28.5 μg L–1 for 144 h. The photochemical efficiency of photosystem II (F v/F m ratio) was significantly reduced at all temperatures by diuron exposure at 32 μg L–1 after 72 h. Inhibition rates was significantly increased with decreased water temperature (P?<?0.01). Intracellular H2O2 levels as an indicator of oxidative stress were also decreased with increasing temperature in both control and diuron treatment groups and were about 2.5 times higher in diuron treatment groups than that of controls (P?<?0.01). Our results suggest water temperatures may affect the toxicokinetics of diuron in freshwater and should therefore be considered in environmental risk assessment.  相似文献   
23.
Short-term exposure datasets of 10 workers exposed to organic solvents and daily average exposure datasets of seven workers exposed to cobalt and organic solvents were analyzed in order to clarify whether these exposure data fit an inverse Gaussian distribution. The goodness-of-fit test showed that time-weighted average (TWA) values with averaging times of 30 min, 60 min and 8 hours can be described by an inverse Gaussian distribution, but not those with averaging times of 7.5 min and 15 min.  相似文献   
24.
IntroductionBleachingwastewaterfrompulppaperplantscontainsmanykindsofchlorinatedorganiccompoundswhichareprovedtobecarcinogenic,mutagenicandrefractory(Gellman,1988;Paasivirta,1988;Garden,1990;Suntio,1988;Vuorinen,1987;Seppala,1988).Severalmethods,inc…  相似文献   
25.
A computer-assisted library search system is described consisting of a data base, pre-search and main search. Odorous air and effluent gas from painting and printing industries were analyzed by gas chromatography-mass spectrometry and the library search system. Main components were 2-methylpropanol, three xylenes, toluene, ethyl acetate and butyl acetate.  相似文献   
26.
Y. Nagai  K. Kaneko 《Marine Biology》1975,29(2):105-108
The omnivorous sea urchin Strongylocentrotus pulcherrimus inhabits the coast of Japan. It also ingests foreign foods, which are not normally present in the natural habitat. In cultures, foreign foods, such as white fish meal, shellfish meal, milk casein, gelatin, soybean meal, yellow corn, alfalfa and yeast were provided in the form of a moist and soft material and their ingestion and digestibility were examined. The foreign foods were prepared by mixing with agar-agar. Digestibility of the diet, and that of nitrogen contained in the diet, was estimated as 54.7 and 64.7% dry weight. Sea urchins cultivated over a period of 5 months on such a foreign diet exhibited 24% increase in wet weight during this period. Occasionally, the ingestion of artificial food suddenly decreased, but was soon resumed upon supplying a hot-water extract of brown algae.  相似文献   
27.
Awareness is needed of sustainability issues that are currently neglected but potentially important. A computer-based approach can highlight unconscious and neglected areas because it can structure vast amounts of knowledge. In this article, we propose a methodology to perceive unconscious areas of sustainability with the support of a computer-based approach, which creates a matrix, named the recognized-unrecognized matrix, which highlights both local and globally neglected problems. A case study is conducted to consider the potential contribution of the aviation industry to sustainability issues. We demonstrate that a citation network analysis is an effective methodology to chart the recognized-unrecognized matrix. We highlight issues of water use in the aviation industry by designing an innovative water and air circulation system, which significantly reduces water and fuel consumption on board airplane flights. We also suggest a new approach to integrating both explicit and tacit knowledge to enable knowledge creation.  相似文献   
28.
Sustainability science requires the development of a theoretical framework to understand, analyze, and design innovation to solve social, economic, and environmental issues. This paper extends the framework of multi-level perspectives (MLP) by introducing a technology readiness level (TRL), and analyzes the innovation of the advanced turboprop (ATP) engine in the aviation industry, also known as a propfan or an open rotor engine, which is one of the most promising engine innovations expected to mitigate climate change. The concept of TRL was introduced to explain the mechanisms of ATP failure in the late 1980s as well as the transition of the geared turbofan (GTF). In this paper, we discuss why ATP and GTF faced different fates although both were developed under the same landscape in the aviation industry. We also discuss the different roles of the socio-technical regime, such as uneven and dynamic opportunity windows, technological readiness, niche stock, institutional support of export products, and the risk of a ‘launch’ customer, at different TRLs. As illustrated in this paper, MLP with TRL is expected to facilitate future interdisciplinary collaboration between social scientists and engineers, and also transdisciplinary expertise between academia and practitioners by supporting analysis and design of the industry’s transition toward a more environmentally friendly regime as well as its effective management.  相似文献   
29.
Differences in colour and shape have been used to discriminate diapause pupae from non-diapause pupae in butterflies. In the present study, we describe a simple discrimination method based on differences in the specific gravity of diapause and non-diapause pupae of large and small white butterflies, Pieris brassicae and Pieris rapae crucivora. When put into water, diapause pupae sink to the bottom (specific gravity is above 1.0), whereas non-diapause pupae float on the surface (specific gravity is below 1.0). Nuclear magnetic resonance microimaging revealed that this difference in specific gravity is due to a difference in the volume of an internal cavity located between the thorax and the abdomen in the pupae. The cavity appears quite early in development. We also examined the cavity in pupae of the unrelated swallowtail butterfly, Papilio xuthus, and found a similar cavity. However, in this species, the cavity is very small and, as a consequence, non-diapause as well as diapause pupae sink in water.  相似文献   
30.
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