Oxygen Isotopic and Chemical Characterization of Soils with Surface Gleyzation from Central and Northeastern Japan

Four soils with surface gleyzation (Humi-stagnic Gleysols; provisional) from central and northeastern Japan are characterized by a combination of oxygen isotopic, chemical dissolution (pyrophosphate and acid oxalate) and X-ray diffraction analyses. Oxygen isotopic composition of quartz indicates residuum of volcanic materials and eolian dust from interior China as major parent materials of the clayey surficial horizons.     

Species diversity of the marine diatom genus Skeletonema in Japanese brackish water areas

The genus Skeletonema includes phytoplankton species that are important primary producers in marine food chains. Brackish waters have been reported to be one of the important habitats of some species of Skeletonema. To elucidate the species diversity of Skeletonema in brackish waters, we investigated three Japanese brackish bodies of water: the coastal waters of Toyama Bay, a tidal area of the Chikugo River, and a constructed reservoir in Isahaya Bay. We used molecular analysis based on large subunit rDNA and fine morphological structure to identify species. Skeletonema costatum s.s. (sensu stricto) was isolated at salinities as low as 0.6, but Skeletonema dohrnii, Skeletonema subsalsum, and Skeletonema tropicum were not found at salinities below 11.0. S. costatum s.s. could survive transfer from a medium with a salinity of 15 to a salinity of 2, but S. dohrnii did not survive in the same experiment. Only S. costatum s.s. germinated from the sediment of a reservoir in which the salinity was 0.1–1.4; incubation conditions included temperatures of 10, 15, 20, 25, and 30 °C and salinities of 5 and 30. Skeletonema costatum s.s. was identified as the species most adaptable to low-level salinity variations throughout its lifecycle.     

Relationships between the primary mineral and the clay mineral compositions of some recent andosols

Relationships between the clay mineralogy and the primary mineral association were studied on seventeen Andosol samples (<3,000 years old) collected from Aomori, Hokkaido, and Iwate. Opaline silica, allophane, and imogolite were predominant in the soils derived from volcanic ashes which contained practically no quartz, while opaline silica, crystalline layer silicates, alumina-rich gel-like materials, and allophanelike constituents were abundant in the soils which contained abundant quartz. There was no positive indication of the presence of allophane in any quartz andesitic Andosols. High contents of finely comminuted amphibole and mica in the quartz andesitic volcanic ashes suggested that the crystalline layer silicates are inherited and are not formed pedochemically from amorphous materials.     

Clay mineralogy of some volcanic ash soils in which cristobalite predominates

The clay mineralogical composition of soils on volcanic ashes from Mashū and Kamuinupuri-dake volcanoes, Hokkaido, which are rich in cristobalite, was determined using petrological, X-ray diffraction, differential thermal, and selective dissolution and differential infrared spectroscopic methods.

The cristobalite occurred in abundance in every size of fraction from coarse sand to clay and every soli from approximately 1,700 to 8,400 years old, and was concluded to be of igneous origin. The major clay minerals were allophanelike constituents and allophane with some layer silicates as the minor clay mineral, being similar to those of andesitic ash soils and different from those of volcanic ash soils containing abundant quartz. The quartz of volcanic ashes was presumed to bederived from the groundmass-equivalent portion of the ashes which had been formed from magma at a low temperature.     

Character impact odorants of high-heat skim milk powder isolated by simultaneous distillation-extraction

To identify the character impact odorant of high-heat skim milk powder (HHSMP), a comparative study using ultrahigh-temperature (UHT) milk was performed. Aroma concentrate was prepared by column adsorption combined with simultaneous distillation-extraction. Aroma extract dilution analysis (AEDA) revealed 58 aroma peaks with flavor dilution (FD) factors ranging from 10 to 3000; from these, 41 compounds were identified and 7 compounds were tentatively identified (FD factor > or = 300). Among these HHSMP and UHT milk components, methyl 2-methyl-3-furyl disulfide and bis(2-methyl-3-furyl) disulfide, which appeared to be generated during the processing of each product, were identified. When the results of the AEDA of both samples were compared, it was considered that the characteristic aroma of HHSMP was not explained by a single compound but instead formed from a mixture of several types of compounds contained in common with the UHT milk. The contribution of these compounds to the aroma of HHSMP was confirmed by an aroma simulation experiment.     

Sustained hypomyelination and high serum thyroid hormone in aged black tremor hamster

Oligodendrocytes and myelin in the corpus callosum of black tremor and normal hamsters aged over 1.5 years were ultrastructurally examined to determine the myelination index (ratio of myelin thickness/diameter of axon), percentage of naked axons, and proportions of oligodendroglial subtypes (light, medium and dark). The mutant hamsters were remarkably hypomyelinated, with a low myelination index and a high proportion of naked axons, and high proportions of the dark subtypes. Serum concentrations of thyroid hormones (T3 and T4) in 6-week-old mutant hamsters were 2-fold (T3) to 3-fold (T4) higher than those of age-matched normal animals. However, in the aged animals (over 1.5 years old) only T4 levels of the mutant hamsters were higher in the mutant than normal hamsters. The black tremor hamsters were hypomyelinated throughout their life and high serum level of thyroid hormones might have played a role in the hypomyelination.     

Bovine ephemeral fever in Taiwan (2001-2002)

Bovine ephemeral fever (BEF), a vector-borne disease of cattle, is caused by the Ephemerovirus of the family Rhabdoviridae. In the past 40 years, Taiwan has had seven BEF epizootics, and we have previously reported the first five. This study summarizes the 2001 and 2002 epizootics; conducted case-control serologic studies on 10 herds involved in the 2001 epizootic; determined whether the recent BEF viruses have varied significantly; and discusses the relationship between epizootic patterns and possible variant BEF viruses. For mature cows that had received at least 2 doses of vaccine before the study, a negative correlation between the prevaccinated (the 3rd dose and after) serum neutralization antibody (SNA) titers and their postvaccinated peak rates was found. When prevaccinated SNA levels were at < or = 32, their postvaccinated SNA levels increased significantly faster (P<0.01) than for those at > or = 32. The glycoprotein gene of isolates from 1999, 2001, and 2002 had a 99.2-99.9% homology, without consistent amino acid variations in the neutralization sites. Phylogenetic analysis of Taiwanese isolates revealed 2 distinct clusters, the 1983-1989 and 1996-2002 isolates. Cross-neutralization tests confirmed the glycoprotein gene sequence analysis results. In conclusion, annual boosters at SNA levels > 32, at more than 2 doses, or at intervals shorter than 6 months are not advisable. The occurrence of frequent small epizootics implies the dominance of BEF virus over host immunity, but not a variant virus.     

Implications of clay mineralogy to the weathering and chemistry of AP horizons of ando soils in Japan

The clay mineralogy of 22 samples of the Ap horizons of Ando soils was determined by a combination of methods. Of these samples, 15 did and 7 did not contain allophane and imogolite. Opaline silica was found in 4 samples, whereas aluminum—humus complexes, iron oxides and layer silicates were found in all samples. The presence of allophane and imogolite and the absence of opaline silica in a few Ap horizons was related to mixing of A₁ horizons and subsoils by cultivation and to lower supplies of organic matter relative to the amounts of aluminum released from volcanic ash by weathering. The contents of 2:1 and 2:1:1 layer silicates and their intergrades were larger in soils in which quartz predominated in fine fractions. It was inferred that aluminum bound with humus and in allophane-like constituents, rather than aluminum in allophane and imogolite, is important in reactions with phosphate and fluoride.     

ABSTRACT of the Articles Printed in Journal of the Science of Soil and Manure,Japan

A contrasting occurrence of clay minerals was found within a soil profile which was derived from volcanic materials in the suburbs of Fukuoka-city, Northern Kyushu. The soil profile is located on an isolated terrace, and the morphological characteristics of the soil correspond exactly to Andosols, so-called Kuroboku soils or Humic Allophane soils.

The clay fraction of upper horizons of the soil consists largely of alumina-rich gel-like materials, gibbsite, and layer silicates such as chlorite and chloritevermiculite intergrades, while that of lower horizons is composed of allophane and gibbsite or halloysite. There was no positive indication of allophane in the upper horizons. Corresponding with the clay mineralogical composition, quartz is abundant in the fine sand fraction of the upper horizons, while the mineral is very scarce or none in the lower horizons, suggesting a close relation between the petrological nature of parent volcanic materials and the mineralogical composition of weathering products. The dominant clay mineral in the volcanic 1.10il might be dependent on the petrological nature of parent materials, and allophane is mostly formed from andesitic materials, and alumina-rich gel-like materials and layer silicates have come from quartz andesitic materials. Allophane would transform to gibbsite or halloysite according to weathering conditions, and aluminarich gel-like materials change to gibbsite under a well-drained condition.

The soil materials have been so greatly weathered that some horizons contain gibbsite of even more than 40 per cent or halloysite over 70 per cent. The morphology and mineralogy are quite similar to so-cailed “non-volcanic Kuroboku soils.”