Vertical distribution of radiocesium in soils of the area affected by the Fukushima Dai-ichi nuclear power plant accident

Presented are results of the study of radiocesium vertical distribution in the soils of the irrigation pond catchments in the near field 0.25 to 8 km from the Fukushima Dai-ichi NPP, on sections of the Niida River floodplain, and in a forest ecosystem typical of the territory contaminated after the accident. It is shown that the vertical migration of radiocesium in undisturbed forest and grassland soils in the zone affected by the Fukushima accident is faster than it was in the soils of the 30-km zone of the Chernobyl NPP for a similar time interval after the accident. The effective dispersion coefficients in the Fukushima soils are several times higher than those for the Chernobyl soils. This may be associated with higher annual precipitation (by about 2.5 times) in Fukushima as compared to the Chernobyl zone. In the forest soils the radiocesium dispersion is faster as compared to grassland soils, both in the Fukushima and Chernobyl zones. The study and analysis of the vertical distribution of the Fukushima origin radiocesium in the Niida gawa floodplain soils has made it possible to identify areas of contaminated sediment accumulation on the floodplain. The average accumulation rate for sediments at the study locations on the Niida gawa floodplain varied from 0.3 to 3.3 cm/year. Taking into account the sediments accumulation leading to an increase in the radiocesium inventory in alluvial soils is key for predicting redistribution of radioactive contamination after the Fukushima accident on the river catchments, as well as for decision-making on contaminated territories remediation and clean-up. Clean-up of alluvial soils does not seem to be worthwhile because of the following accumulation of contaminated sediments originating from more contaminated areas, including the exclusion zone.     

Effect of Long-term Fertilizer Application on the Concentration and Solubility of Major and Trace Elements in a Cultivated Andisol

The concentrations and solubility of major and trace elements in soils collected from a field for long-term experiments maintained for more than 60 years and the neighboring area were investigated in order to reveal the influence of soil management on their behavior in soils. No obvious differences in the element concentrations in soils were observed except for P and U, whose concentrations were elevated in the surface soils of the experimented field because of the long-term application of phosphate fertilizers. Soil acidification associated with the successive applications of potentially acid fertilizers had changed the solubility of many elements as follows: the solubility of Li, Be, Al, Mn, Co, Zn, Y, Cd, Ba and rare earth elements increased, while the solubility of P, As, Se, Nb, Sb, Mo and V increased by liming. In the uncultivated soils, the concentrations of Fe, Zr, Nb, Hf and Th in the water extracts were relatively high, and a certain amount of these elements in the water extracts may occur in colloidal forms.     

Transport of Atmospheric Pollutants from East Asia

Air-borne measurements of air pollutants transported from northeast Asia to Japan and the Pacific Ocean were carried out three times from 1996 to 1999 over the seas between Japan and Asian Continent. Those campaigns were named PEACAMPOT II under auspices of the IGAC/APARE program. A transport pattern of a highly polluted air mass from central China was found. Such air mass was driven by the quick movement of low pressure traveling from Taiwan area to the northeast of Japan. This finding supported well the results of modeling studies for long-range transport of atmospheric pollutants from East Asia.     

Suspected panosteitis in a crossbred calf

A male crossbred calf developed a limp and pain upon deep pressure on the right hind limb and the right forelimb. The radiographic findings of affected limbs and pathological findings of bone biopsy were similar to those observed in canine panosteitis. This is the first case of suspected panosteitis reported in cattle.     

Effect of food amount and temperature on growth rate and aerobic scope of juvenile chum salmon

Offshore migration of Pacific salmon Oncorhynchus spp. is partly triggered by increasing body size and high motility in the early stages of life. The survival of juvenile salmon may depend on their growth rate during the first few months in the sea, and this factor partly regulates the dynamics of adult populations. Here, we assessed the effects of water temperature and food availability on the growth of juvenile chum salmon O. keta. In addition, by combining the measurements of metabolic performance for growth and activity (Absolute Aerobic Scope: AAS) with a bioenergetics model, we estimated the energy allocation for different activities in the juveniles. Under high temperatures (14 °C), juveniles reared at low food levels (1% body weight) allocated less than half their energy for growth than those reared at high food levels (4% body weight). These findings suggest that high temperature and low food level constrain the growth of juveniles, providing an insight into the effect of the recent increase in warm and low-nutrient water masses on survival of juveniles and catches of adult chum salmon on the Pacific side of Honshu Island, Japan.

     

Phylogenetic Analysis of Soybean-Nodulating Rhizobia Isolated from Alkaline Soils in Vietnam

In order to analyze the phylogeny of soybean-nodulating bacteria in alkaline soils in Vietnam, indigenous soybean-nodulating bacteria were isolated from root nodules by cultivating three kinds of Rj -soybean cultivars on two alkaline soils in Vietnam. The 120 isolates were classified into two major genera of soybean-nodulating rhizobia, namely Bradyrhizobium and Sinorhizobium genera, based on a growth analysis on medium and PCR-RFLP analyses of 16S rDNA and of the 16S–23S rDNA internal transcribed spacer (ITS) region. Most of the isolates of B. japonicum were extra-slow-growing and their ITS types were similar to that of B. japonicum USDA 135. They were not isolated from the soybean cultivar CNS used as Rj₂Rj₃ genotype. Isolates of Sinorhizobium were divided into two groups, S. fredii and S. sp., based on a PCR-RFLP analysis of 16S rDNA. Furthermore, PCR-RFLP analysis of the 16S–23S rDNA ITS region enabled to separate them into five types, three ITS types associated with S. fredii and two with S. sp. Sinorhizobium was frequently isolated from the three soybean cultivars on two soils. From the isolate ratio, it was suggested that B. japonicum strains similar to B. japonicum USDA 135 and S. fredii predominated in the alkaline soils of Vietnam. Additionally, our findings indicated that the Rj -genotypes affected not only the compatibility, but also the preference for nodulation between the host soybean and rhizobia.     

One-step immunochromatography assay for detection of high-level canine serum trypsin-like immunoreactivity

We developed a one-step immunochromatography assay kit to measure high levels of canine trypsin-like immunoreactivity (cTLI) for bedside estimation of canine pancreatitis. The serum cTLI level can be determined within 10 min by visual comparison of color strengths in the test and reference zones. The serum cTLI levels determined by this method correlate well with canine TLI-ELISA and can be classified into 3 categories: cTLI levels higher than 60 ng/ml were considered positive; 20-60 ng/ml, weakly positive; and less than 20 ng/ml, negative. Twelve dogs suspected of pancreatitis were examined using this method; 4 dogs were positive, 2 were weakly positive, and 6 were negative. This test can detect a high level of serum cTLI and a positive result in the TLIH test will provide critical information for evaluation of pancreatitis in dogs.     

Distinctive expression of a zinc-binding protein in rice callus grown in medium with high zinc concentration

We investigated the growth, contents of water-soluble protein and free amino acids of the callus of japonica rice (Oryza sativa L. cv. Nipponbare) cultured in liquid N6 medium containing a high concentration of zinc. Furthermore, we determined the N-terminal amino acid sequence of a Zn-binding protein expressed in large quantities in the callus. The addition of Zn stimulated the growth of the callus and increased the Zn concentration. The callus subjected to the high-Zn treatment (hereafter referred to as CHZn) contained a larger amount of soluble proteins and a smaller amount of free amino acids than the control callus. Zinc-binding proteins were separated by affinity chromatography. The SDS-PAGE pattern of these proteins showed a distinctive protein band of about 29 kDa. Especially, CHZn contained larger quantities of 29 kDa protein than the control callus. Twenty-seven N-terminal amino acids of the protein were sequenced as DYAPMTLTIVNNCPYPVWPGIQANSGH. Results of homology search to the amino acid sequences from the nr-aa database and the dbEST database suggested that this 29 kDa protein may be a novel zinc-binding protein and that the protein may regulate the concentration of free zinc in the cytoplasm of callus cells through its binding to zinc ions.     

Thymoma and multiple thymic cysts in a dog with acquired myasthenia gravis

An anterior mediastinal cystic lesion in an 11-year-old mongrel dog was examined. The dog showed dysbasia and vomiting due to megaoesophagus, and anterior mediastinal round mass lesion, approximately 35 mm in diameter, was found by X ray. Based on clinical examinations, the dog was diagnosed as acquired myasthenia gravis and was successfully controlled by anticholinesterase treatment for approximately 4 months. The dog died of thermic stroke and was necropsied. Grossly, fatty tissues with cysts containing yellowish fluid and white nodules were found in the anterior mediastinal area. Histopathologically, multiple cysts, neoplastic tissues, and atrophic thymus were found within the examined tissues. The cysts were lined by thin wall consisting of ciliated long cuboidal and non-ciliated round cells and were filled with eosinophilic colloidal fluid. Some extended cysts contained neoplastic foci within their lumen and walls. The neoplastic tissues consisted of mixed population of large epithelial cells with abundant clear cytoplasm and large oval nuclei, and lymphocytes. Immunohistochemically, proliferating epithelial cells were intensely positive for keratin and cytokeratin, and more than half number of infiltrating lymphocytes were intensely positive for CD3 suggesting T cells. All these findings indicate the neoplastic lesion is thymoma and multiple cysts are considered as thymic or brachial cleft cysts.