Transformation of humus in upland soils,Japan

In the previous reports¹⁾²⁾, we published the significant relationship between methoxyl content and other properties of humus. In order to prove that methoxyl content decreased with the progress of humification and that this amount might be used as an index of the degree of humification, we investigated the deformation of humic acid by acid treatment.     

Formation of humus profile in upland soils

It has generally been accepted that humus and its C/N ratio decrease with the depth of soil profile.     

Applicability of a combined staining method with fluorochromes for the visualization of microbial cells in a soil thin section

Staining of microbial cells in a soil thin section provides useful information about the role of soil as an ecological niche by relating the in situ distribution of microorganisms to the state of pores under undisturbed conditions. For technical improvement, we developed a procedure consisting of a combined staining method with 5-sulfofluorescein diacetate (SFDA), a metabolic type fluorochrome, and magnesium salt of l-anilino-8-naphthalene sulfonic acid (Mg-ANS), an adsorption type fluorochrome, in order to detect and differentiate the living microbial cells from the dead ones in a single soil thin section. Using images under a fluorescence microscope, we also examined the applicability of SFDA for staining microbial cells embedded in soil thin sections, which had seldom been attempted. Through this study, we confirmed the following facts: i) combined staining with SFDA and Mg-ANS can be achieved without major modification of the general procedure for thin section preparation, ii) staining with SFDA can be applied to soil thin sections, and iii) detection of in situ distribution and differential identification of the living and dead microbial cells may be possible by the proposed combined staining method.     

Relative Contribution of Endocrine-disrupting Chemicals to the Estrogenic Potency of Marine Sediments of Osaka Bay,Japan

Water, Air, &; Soil Pollution - Karst systems harbor large groundwater resources for human consumption and represent an important habitat for rare and unprotected specialized animals, the...     

Application of the vibration method with additional mass to timber guardrail beams

This study examined whether or not weight, density, and Young’s modulus can be accurately measured by vibration test without weighing beams for timber guardrails. Bending vibration tests with and without the concentrated mass were performed on small clear round bars without the pith of spruce and cedar and on actual size round bars with the pith of cedar for the timber guardrail. The following results were obtained. The vibration method with additional mass could be applied to the round bar as well as the rectangular bar. It is possible that resonance frequency was decreased by the sawn split in the horizontal tapping. It is believed that the free ends condition is easier to realize than the fixed ends condition for cross beams for timber guardrails. The weight of the cross beam for the timber guardrail could be accurately estimated by the vibration method with additional mass under several testing conditions.     

Pathogenesis of systemic Mycobacterium avium infection in pigs through histological analysis of hepatic lesions

Mycobacterium avium causes systemic infections through primary intestinal lesions in pigs. However, its pathogenesis is not well understood. The aim of this study was to confirm the effects on swine after enteral infection. One hundred and twelve pigs with hepatic lesions infected with M. avium were used in this study. We investigated the involvement of other organs and the distribution of hepatic lesions in the lobular structure. Most lesions involved the mesenteric lymph nodes. Hepatic lymph nodes were the secondary nodes involved. In 74 cases (66.1%), the hepatic lesions were predominantly distributed in the portal tract of the affected livers. The other 38 cases (33.9%) showed granulomatous lesions in the hepatic lobule. Many cases showed interface hepatitis. There was a significant relationship between focal lesions within hepatic lobule and splenic lesions. These findings suggest that granulomatous lesions formed in hepatic lobules upon establishment of bacteremia in pigs systemically infected with M. avium.     

QTL Analysis for Traits Associated with Feeding Value of Straw in Rice(Oryza sativa L.)

Genetic improvement of the digestibility of rice strew for increasing the utilization of the whole rice plant as feedstuffs is an important way to solve the feedstuffs shortage in southeastem China. To elucidate the genetic basis of the traits affecting the digestibility of rice straw, a rice population of 111 recombinant inbred lines (RILs) derived from a cross of Nekken 2xGaya was used to map the quantitative traits loci (QTLs) for in vitro dry matter digestion (IVDMD), the percentages of nonstructurel carbohydrate (NSC) and acid detergent fiber (exclusive of residual ash, ADFom) in 2005 and 2006. IVDMD was positively correlated with NSC, and negatively correlated with ADFom. A total of 16 QTLs were detected in the two years, and the amounts of variation explained by individual QTLs ranged from 6.9% to 15.5%. Some QTLs for IVDMD and ADFom on chromosome 2 were detected in the two years. On chromosome 2, the interval RM475-RM3515 contained QTLs for IVDMD in the two years and for NSC in 2006 only, while the interval RM3874-RM5305 influenced ADFom in the two years and NSC in 2005 only. At those loci, Gaya contributed favorable alleles to IVDMD and NSC, while Nekken 2 contributed positive alleles to ADFom.     

Maturation of Theileria sergenti in salivary glands of Haemaphysalis longicornis induced by temperature stimulation

The parthenogenetic Haemaphysalis longicornis larvae engorged on cattle naturally infected with Theileria sergenti were reared at 24 degrees C. The resultant nymphal ticks were incubated at 37 degrees C to clear the effect of incubation on the development and maturation of sporozoites. The sporozoites in the salivary glands of the nymphal ticks exposed to 37 degrees C for 16 days were observed by the methyl green pyronin staining method. The ticks exposed to 37 degrees C were ground up in a mortar and the supernatant of the tick suspension in PBS was inoculated into cattle. The cattle showed parasitemia and specific antibody response 18 days after inoculation. Consequently, the parasites in the tick salivary glands became infective to cattle by incubating infected. H. longicornis nymphs at 37 degrees C.