Molecular heterogeneity in clinical isolates of Malassezia pachydermatis from dogs

Molecular investigation of 16 strains, conventionally identified to be Malassezia pachydermatis, isolated from dogs in Japan was carried out by random amplification of polymorphic DNA (RAPD) and chitin synthase 2 (CHS2) gene sequence analyses. The RAPD band patterns of 13 clinical isolates were identical to that of standard strain of M. pachydermatis (CBS-1879). The other three clinical isolates were different from the standard strain of M. pachydermatis in RAPD patterns, and two of the three isolates were identical. About 620 bp genomic DNA fragments of the CHS2 gene were amplified from the same 16 clinical isolates of M. pachydermatis by polymerase chain reaction (PCR) and sequenced. The phylogenetic analysis of the nucleotide sequences of CHS2 gene fragments of the 16 clinical isolates revealed that the 13 strains were genetically very close to the standard strain of M. pachydermatis and the other two isolates were genetically close to the standard strain of M. furfur rather than M. pachydermatis. The remaining one isolate was phylogenetically distinct from all the seven Malassezia species reported so far.     

Nitrogen-fixing activity in decomposing litter of three tree species at a watershed in eastern Japan

Nitrogen fixation during litter decomposition was studied for 34 months using litterbags containing newly fallen litter of coniferous species Cryptomeria japonica and Pinus densiflora and that of deciduous species Quercus serrata. Litterbags were set in contact with the forest floor in a deciduous broad-leaved forest near the top of a slope and in a C. japonica stand at the middle of the slope at a watershed in eastern Japan. Nitrogen-fixing activity, estimated by acetylene reduction after 16 and 19 months of incubation, was 62.65–3.86 nmoles C₂H₄ h⁻¹ g⁻¹ DW in Cryptomeria litter, but only 1.07–0.09 in Pinus and 0.72–0.04 in Quercus. The rate of N increase in decomposing litter was highest in Cryptomeria. Fungal biomass in decomposing litter, estimated by ergosterol content, increased during the initial 16 months of incubation in Cryptomeria and Quercus, and during the initial 19 months of incubation in Pinus. The litter decomposition rate was highest in Cryptomeria among the three species, due to increased N content and fungal biomass in Cryptomeria litter. Thus, N increase in decomposing Cryptomeria litter affects the subsequent N dynamics and decomposition pattern.     

Curing and degradation processes of cement-bonded particleboard by supercritical CO<Subscript>2</Subscript> treatment

This study examined the effects of supercritical CO₂ treatment on the curing and degradation of cementbonded particleboard (CBP). Significant correlations were found between the supercritical CO₂ treatment and mechanical properties during both curing and degradation processes. Internal bond (IB) strength, modulus of rupture (MOR), and modulus of elasticity (MOE) values of CBP achieved their maximums by supercritical CO₂ treatment in 30 min. These conditions indicated that supercritical CO₂ treatment accelerates the curing process rapidly and enhances the mechanical properties of the CBP. However, these values decreased in treatment from 60 min to 10 days and had a negative effect on board performance, indicating that supercritical CO₂ treatment over a longer time span leads to degradation of the CBP. Furthermore, X-ray diffractometry (XRD), thermal gravimetry (TG-DTG), and scanning electron microscopy (SEM) observation clarified that the mechanisms of degradation are directly affected by the mineralogical composition of the system, in par ticular, by the calcium carbonate content as caused by carbonation.     

Induction of T cell anergy by the treatment with IL-10-treated dendritic cells

In order to apply for reducing graft versus host disease in allogeneic stem cell transplantation, the study concerning the induction of specific T cell anergy was designed. Normal allogeneic lymphocytes, which were co-cultured with IL-10-treated immature dendritic cells in the first mixed leukocyte culture (MLC), were cultured with mature dendritic cells of the same origin as IL-10-treated immature dendritic cells in the second MLC. By co-culturing with IL-10-treated immature dendritic cells, the response of normal lymphocytes to mature dendritic cells cultured from the same individual as that of IL-10-treated dendritic cells was markedly reduced, compared with the lymphocytes cultured with non-treated dendritic cells or IL-10-treated dendritic cells from a third party individual. The present study demonstrated that antigen specific T cell anergy was generated by priming allogeneic lymphocytes with IL-10-treated immature dendritic cells. These data suggested the applicability of IL-10-treated recipient dendritic cells for the induction of recipient cell-specific donor T cell anergy in donor graft.     

Relationship between <Superscript>137</Superscript>Cs concentration and potassium content in stem wood of Japanese cedar (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>)

To utilize forest resources in areas affected by fallout from the Fukushima Daiichi Nuclear Power Plant accident, it is important to understand the mechanisms of ¹³⁷Cs movement through the stem wood of contaminated trees. Understanding the mechanism of absorption and migration of ¹³⁷Cs to stem wood is necessary for clues to the future prediction of the transition of ¹³⁷Cs to xylem. In the present study, radial variations in ¹³⁷Cs concentration were investigated in Japanese cedar (Cryptomeria japonica D. Don) trees collected 1 year and 10 months after the accident. Additionally, the relationship between ¹³⁷Cs concentration and potassium (K) content was established. Trees with a higher moisture content and lower lightness value in heartwood tended to have a higher ¹³⁷Cs concentration in the heartwood. In these trees, ¹³⁷Cs concentration peaked at the heartwood–sapwood boundary and gradually decreased toward the pith. By contrast, K content within the heartwood remained nearly constant along the radial direction. The heartwood-to-sapwood ratio of ¹³⁷Cs concentration was significantly positively correlated with that of K content. Based on these results, we suggest that ¹³⁷Cs movement from sapwood to heartwood might be related to the K content ratio of heartwood and sapwood.     

The infrared absorption spectra of soil components

In the preceding paper (1), the authors had determined the infrared absorption spectra of humic acids obtained from various soils of different origin, and concluded that they were, according to their infrared characteristics, classified into four groupes, i.e., A,B,Rp, and P types. After that, the authors conducted some experiments of the infrared spectra of soil components in order to get some information on the nature of so-called humin, and forms of soil clay and clay humus complex. The infrared spectra of silica, sesquioxides, clay minerals and humates of aluminium, iron and calcium were also determined for comparison. These experimental results will be given in this paper.     

Aminopyrifen,a novel 2-aminonicotinate fungicide with a unique effect and broad-spectrum activity against plant pathogenic fungi

Aminopyrifen is a novel 2-aminonicotinate fungicide with unique chemistry and a novel mode of action. The fungicide showed high antifungal activity mainly against Ascomycetes and its related anamorphic fungi under in vitro and pot conditions (EC₅₀ values: 0.0039–0.23 mg/L and 1.2–12 mg/L, respectively). The active ingredient strongly inhibited germ-tube elongation of Botrytis cinerea below 0.1 mg/L and invasion into a plant. The compound exhibited no cross-resistance to commercial fungicides in B. cinerea. The antifungal agent showed high preventive efficacy and translaminar action. In the field, aminopyrifen controlled gray mold and powdery mildew at 150 mg/L. Our findings suggest that aminopyrifen is useful for protecting crops from various plant pathogens.