The Fukushima nuclear accident led to deposition of radionuclides into the freshwater fishery ground of ayu Plecoglossus altivelis. For the purpose of more comprehensive understanding of the radioactive contamination, cesium-137 (137Cs) was analyzed in running water, muddy sediment, attached algae, and ayu using samples from three river systems with different levels of contamination within Fukushima Prefecture in summer and autumn 2011. The amount of 137Cs contained in water as well as in sediment declined over an interval of two months, although the concentration in sediment samples was up to 10,000-fold higher than that in water samples. The changes in 137Cs concentration of algae showed different courses among the three river systems, the concentration being greater in autumn in the river systems with high and moderate radioactive contamination. 137Cs detected within a single stock of ayu appeared to be excreted rather rapidly with a calculated half-life of approximately 39 days, while the concentration ratio ranged from 103 to 104 l/kg, attaining higher levels than previously reported. These findings indicate that the most important pathway of 137Cs into ayu is via intake of algae as food but that the retention time of 137Cs inside ayu is relatively short. 相似文献
To examine the digestibility of common reed (Pharagmites communis Trin.) silage and effects of inclusion levels in the diet of breeding cows on nutrient intakes, ruminal fermentation and nutrient status, two digestion trials using four sheep and cows, respectively, at the maintenance stage were conducted. In the trial using sheep, common reed silage contained 20% crude protein (CP) and 50% total digestible nutrients (TDN) on a dry matter basis. In the trial using cows, treatments were the control (92.4% Sudangrass hay and 7.6% soybean meal) and CS25, CS50 and CS80 (replacing 25%, 50%, and 80% of the control with silage, respectively). The intake and sufficiency rate of CP increased by increasing the silage level in the diet (P <0.05), and the CP requirements of cows at maintenance was satisfied in CS80. In contrast, the sufficiency rate of TDN decreased in CS80, although it was 99.8%. Ruminal pH and NH3‐N concentration changed among the treatments (P <0.05); however, the blood metabolites were not affected by silage. The results indicated that including common reed silage of up to 80% in the diet of breeding cows was possible and did not have adverse effects on the blood metabolites. 相似文献
Adults of Carassius auratus grandoculis ascend from Lake Biwa, Japan, into riparian paddy fields via agricultural drainage systems for the purpose of spawning. However,
land improvement works conducted in the second half of the twentieth century have brought about obstacles for passage of the
fish, and several restoration projects to recover the migratory environment are being attempted. A continuous Markov process
model is presented to scientifically support such a project, defining an ascending probability that quantitatively assesses
the ability of an agricultural drainage system with hydraulic structures for the ascent of the fish. Computational methods
are developed to numerically obtain flow fields of the agricultural drainage system and then the ascending probability in
the entire spatio-temporal domain. The values of model parameters are deductively inferred, referring to results of field
observations. From the computational results of the ascending probability in the agricultural drainage system, effects of
hydraulic structures allowing ascent of the fish are clarified. 相似文献
1. The endosteal cellular response occurring in the early stages of medullary bone formation was histologically examined in the femurs of male Japanese quail treated with oestrogen and antioestrogen. 2. The numbers of endosteal cells decreased, and preosteoblasts and osteoblasts increased, on the endosteal surface following oestrogen treatment. 3. After oestrogen and anti-oestrogen treatment the numbers of preosteoblasts and osteoblasts on the endosteal surface did not increase. However, endosteal cells slowly decreased in number and osteoclasts increased. 4. This study demonstrates that differentiation of osteoblasts is induced by oestrogen stimulation and suggests that osteoclasts occur by oestrogen inhibition on the endosteal surface. 相似文献
Unique secondary metabolites, glucosinolates (S-glucopyranosyl thiohydroximates), are naturally occurring S-linked glucosides found mainly in Brassicaceae plants. They are enzymatically hydrolyzed to produce sulfate ions, D-glucose, and characteristic degradation products such as isothiocyanates. The functions of glucosinolates in the plants remain unclear, but isothiocyanates possessing a pungent or irritating taste and odor might be associated with plant defense from microbes. Isothiocyanates have been studied extensively in experimental in vitro and in vivo carcinogenesis models for their cancer chemopreventive properties. The beneficial isothiocyanates, glucosinolates that are functional for supporting human health, have received attention from many scientists studying plant breeding, plant physiology, plant genetics, and food functionality. This review presents a summary of recent topics related with glucosinolates in the Brassica family, along with a summary of the chemicals, metabolism, and genes of glucosinolates in Brassicaceae. The bioavailabilities of isothiocyanates from certain functional glucosinolates and the importance of breeding will be described with emphasis on glucosinolates. 相似文献
The Hayabusa spacecraft successfully recovered dust particles from the surface of near-Earth asteroid 25143 Itokawa. Synchrotron-radiation x-ray diffraction and transmission and scanning electron microscope analyses indicate that the mineralogy and mineral chemistry of the Itokawa dust particles are identical to those of thermally metamorphosed LL chondrites, consistent with spectroscopic observations made from Earth and by the Hayabusa spacecraft. Our results directly demonstrate that ordinary chondrites, the most abundant meteorites found on Earth, come from S-type asteroids. Mineral chemistry indicates that the majority of regolith surface particles suffered long-term thermal annealing and subsequent impact shock, suggesting that Itokawa is an asteroid made of reassembled pieces of the interior portions of a once larger asteroid. 相似文献
In the endodermal cells of the yolk sac membrane of chicken embryos incubated for 12 to 18 d, the activity of glucose‐6‐phosphatase (G‐6‐Pase) was high, the activity of acid phosphatase (Acid Pase) was moderate, the activities of lactate dehydrogenase (LDH) and of glyceraldehyde‐3‐phosphate dehydrogenase (G‐3‐PDH) were low, and succinate dehydrogenase (SDH) and alkaline phosphatase (Alk Pase) activities were not detected. On the day before hatching, however, SDH became evident with low activity, and the activities of Acid Pase, LDH and G‐3‐PDH increased and remained higher until the day after. Five days after hatching, there were marked decreases in the activities of all the enzymes except SDH. Alk Pase was not detected at any time. The function of the yolk sac endo‐derm in the absorption of yolk is discussed in the light of these observations. 相似文献
Buffer mainly consisting of 100 g of sodium bicarbonate and 30 g of magnesium oxide was added to the feed per head per day and given for 8 months to groups of 92 cows of milk fat depression. Milk fat increased from 3.06% (pre-treatment) to 3.68% at 4 months and 3.71% at 8 months post-treatment. Solids-not-fat was slightly increased by the buffers. Milk production was not affected. The number of rumen protozoa increased from 2.85 X 10(5)/ml (pre-treatment) to 9.61 X 10(5)/ml at 8 months post-treatment and the kinds of protozoa diversified. An increase of acetate and decrease of propionate were observed together with increased milk fat at 8 months post-treatment. An increase of hematocrit, lactate dehydrogenase, sodium and potassium, and a decrease of cholesterol and gamma-glutamyl transpeptidase in blood were recognized after the treatment. The incidence of disease was reduced. There was a significant correlation between increased milk fat percentage and increase in the number and the kinds of protozoa. 相似文献
From the distribution of enzymes, the alveoli of a uropygial gland may be divided into inner and outer zones ; the former being the region near the cavity, and the latter the peripheral region of the gland.
In the inner zone, there appeared strong activities of 17β‐hydroxy‐steroid dehydrogenase (17β‐OH‐SDH), 30α‐OH‐SDH, glucose‐6‐phosphate dehydrogenase (G‐6‐PDH), lactate dehydrogenase (LDH), NAD‐dependent malate dehydrogenase (MDH) and acid phosphatase (Acid Pase) weak activities of succinate dehydrogenase (SuDH), NADP‐dependent MDH, monoamine oxidase (MAO) and non‐specific esterase (Etase), but no activity of β‐hydroxybutyrate dehydrogenase (β‐HbDH).
In the outer zone, there appeared strong activities of LDH and MDH (NAD), moderate activities of 17β‐OH‐SDH, 3α‐OH‐SDH, G‐6‐PDH and β‐HbDH, weak activities of SuDH, MDH (NADP) and MAO, but no activities of Etase and Acid Pase.
The results were negative concerning ?5‐3β‐OH‐SDH, glutamate dehydrogenase, a‐glycerophosphate dehydrogenase, phosphorylase and alkaline phosphatase in both zones. From these results, it was concluded that there must be functional differences between the zones, and that only a part of the metabolic pathways of steroids is being performed. 相似文献