Our field survey showed that thequality of shallow groundwater around the KatsuraRiver in the Kyoto Basin was strongly affected by theinfiltration of river water. Furthermore, that thedeterioration of the groundwater in the southern areato the west of the Katsura River may be related to theincrease in groundwater extraction. To clarify themechanism of groundwater deterioration, we havedeveloped a stochastic method to simulate groundwaterflow. The results showed that there was a largereduction in the groundwater level where groundwaterextraction was intense and recharge flowed from theKatsura River to the high extraction areas in thesouthern region. Another simulation showed that if thegroundwater extraction was 10% of the present removalrate, there would be little recharge from the KatsuraRiver into the groundwater and the quality of thegroundwater would be improved. Thus, we conclude thatthe cause of groundwater deterioration is probably dueto the induced recharge of deteriorated river waterfrom the Katsura River. 相似文献
A method for the determination of Ag in soils using atomic absorption spectrometry is described. The method involves the extraction of Ag from soil by boiling with 6 M HC1 followed by separation of the extracted Ag into methylisobutylketone (MIBK) using sodium N, N-diethyldithiocarbamate (DDTC) as a complexing agent. Silver is determined in the MIBK by direct aspiration into a flame atomic absorption spectrophotometer. The detection limit (S/N=2) for this method is 0.0001 mg L?1 for aqueous solution and 0.002 mg kg?1 for soil. The Ag content of even unpolluted soils can be determined by this method. The determination of Ag using this method was shown to be unaffected by the presence of various ions in the soil. The method was able to recover nearly 100% of Ag added to soil and approximately the same amounts of soil Ag were determined using this method as with HF-H2SO4 decomposition. For 3 reference soils of the Canadian Certified Reference Materials Project (CCRMP), the Ag values obtained by this method were the same as the values determined by Ebarvia et al. (1988). The amounts of Ag in the soils sampled in the Ichi River basin and the Ichi River sediments were determined using this method. This area has been polluted by Cd, Cu, Pb, and Zn discharged from the Ikuno Mine and Smelter. The Ag values ranged from 0.27 to 6.89 mg kg?1 which were much higher than the values of the unpolluted soils. 相似文献
The effect of climate conditions and strong thinning on the soil organic layer, surface soil, and nitrogen and water utilization
by plants was evaluated for hinoki cypress forests in Shikoku and Kinki districts in Japan. Thirty-five forests were selected
in Kochi, Ehime, Kagawa and Kyoto prefectures. The mean annual temperate of the studied forests ranged from 9.6 to 16.3°C,
and the mean annual precipitation ranged from 1,350 to 3,960 mm. Carbon and nitrogen content in the organic layer decreased
with increasing mean annual precipitation. In high precipitation areas, carbon and nitrogen content in the organic layer would
be lower due to rapid decomposition with low soil acidity and due to loss of litter because of heavy rainfall. Carbon and
nitrogen content in the surface soil at 0–5 cm depth decreased with increasing mean annual temperature, but was not related
to mean annual precipitation. The results indicate that loss of organic layer by raindrops in a high precipitation area causes
lower nitrogen availability for plants. Strong thinning significantly reduced carbon and nitrogen content in the organic layer
but did not affect nitrogen concentration and δ13C in leaves. These results suggest that climate conditions and strong thinning can affect carbon and nitrogen content in the
organic layer and subsequent nitrogen availability in soil, but strong thinning does not appreciably affect nitrogen and water
utilization by hinoki cypress. 相似文献
To clarify the fundamental regulation mechanism against indigenous bacterial proliferation in the alimentary tract, we immunohistochemically examined the localization of 4 bactericidal peptides (BP) in the rat digestive exocrine glands. In the upper alimentary tract, lysozyme was detected in the gustatory, extraorbital lacrimal and parotid glands. Secretory phospholipase A2 (sPLA2) was detected in the extraorbital lacrimal glands. β-defensin1 was detected in the gustatory and extraorbital lacrimal glands. β-defensin2 was detected in the Harderian glands. In the stomach, β-defensins were detected in the gastric superficial epithelial cells. In the small and large intestines, only lysozyme and sPLA2 were detected in the Paneth cells. In the cecum, all 4 BP were detected in the middle to apical portions of the crypts, and only sPLA2 was detected in the basal portion. No BP were localized in other exocrine glands associated with the alimentary tract. In addition, all 4 BP were also detected in the columnar epithelial cells of the apical portions of intestinal villi. In the intestinal superficial epithelial cells, lysozyme and β-defensins were detected in the ascending colon, whereas only β-defensin1 was detected in the descending colon and rectum. These results suggest that BP are mainly secreted from exocrine tissues in the initial portion of the digestive tract and play a role in host defense against indigenous bacteria throughout the digestive tract. Part of the BP in the chyme might be absorbed by the epithelium at the most inner sites of mucosae in the small and large intestines. 相似文献
Abstract A series of experiments has been conducted on the N2 fixation in the paddy soils by the authors (1–4). The amount of organic substrates for microorganisms and the degree of reduction of the soil are found to be two major factors affecting the N2-fixing activity of the heterotrophic microorganisms in the submerged soil. Organic debris, rice root and their neighboring soils are identified to be the important micro-sites for the heterotrophic N2 fixers. The organic debris and the rice root are considered to play dual roles by supplying the organic substances; (1) increase of the population of the heterotrophic N2 fixers—the amount of nitrogenase, (2) preparation of the reduced conditions favorable for the nitrogenase activity. However, it is not yet clearly known which of these two roles of the organic substrates is more essential to the N2-fixing activity in the paddy soil. In addition, it is expected that there must be some differences between the organic debris and rice root in their contribution to the N2 fixation in the paddy soil. An experiment was carried out to clarify these problems. Moist soil sample was collected from the plough layer of the paddy field at Central Agric. Exp. Sta. in Konosu City, Saitama Pref., passed through a 5 mm sieve and placed in pots (3 kg moist soil/pot). Ammonium sulfate, calcium superphosphate, and potassium chloride at the rate of 0.4-0.4-0.4 (N-P2O5-K20) g/pot were incorporated into the soil 7 days before transplanting. Split application of ammonium sulfate at the rates of 0.2 and 0.4 g N/pot were also incorporated at 30 and 41 days after transplanting respectively. These pots were divided into three series; planted (P-series), non-planted (N-series), and non-planted and applied with organic manure (O-series). In case of O-series, 60 g of fairly rotted organic manure was applied to each pot. Each pot of P-series was planted with two 4O-day-old seedlings of rice plant at 7 days after submergence. The Nseries was regarded as a control. Each series was not replicated in this preliminary experiment. 相似文献
Veterinary Research Communications - This study investigated the effects of age, sex and breed on serum cystatin C (Cys-C) and creatinine in small breed dogs. This retrospective study included 250... 相似文献
A critical component of many releasing projects is the identification and subsequent implementation of optimal release strategies
that can decrease post-release predation mortalities. We performed laboratory experiments to investigate whether acclimation
to shelters affects the post-release survival of hatchery-reared black-spot tuskfish Choerodon schoenleinii in the presence of a reef-resident predator, the white-streaked grouper Epinephelus ongus. Tuskfish were exposed to groupers under three different experimental conditions/treatments: (1) acclimation of fish to shelters
prior to their exposure to groupers; (2) no acclimation of fish to shelters, but with shelters available during their exposure
to groupers; (3) fish not acclimated to shelters and no shelters available during their exposure to groupers. Tuskfish that
were acclimated to shelters utilized shelters more frequently than did non-acclimated fish, and the survival rate of acclimated
fish was higher than those of fish in the other treatments. These results suggest that pre-release acclimation to shelters
improves the post-release survival of hatchery-reared black-spot tuskfish. 相似文献
Modori-inducing proteinases (MIPs) in horse mackerel and the effect of sodium citrate on the modori phenomenon were investigated. Cysteine protease caused the modori phenomenon only at 60 ℃, while metalloproteinase caused it at both 60 ℃ and 70 ℃. Moreover, the autolysis of myofibrillar proteins was mainly inhibited by ethylene diamine tetra-acetic acid (EDTA), verifying the existence of insoluble metalloproteinase. From the results comparing thermal gel properties and protease activities, we confirmed that increased activity of insoluble metalloproteinase corresponded to the weakening of the thermal gel. Thus, insoluble metalloproteinase was the major MIP in horse mackerel. Moreover, sodium citrate could markedly inhibit insoluble metalloproteinase activity at 60 ℃. The addition of sodium citrate significantly improved the breaking force of the thermal gel at 60 ℃ and 70 ℃, suggesting that sodium citrate could suppress the modori phenomenon by inhibiting insoluble metalloproteinase. Therefore, it is desirable to use sodium citrate in horse mackerel surimi-based products to prevent the modori phenomenon.