Carbon resources of residue and manure in Japanese farmland soils

This study calculated the carbon (C) input to farmland soils in Japan in an effort to investigate the potential increase in soil C of farmland soils by proper application of crop residues (straw and root) and manure. The calculation was based on inventory and activity data obtained from statistics, literature sources and inquiry reports for the year 2005. The total C resources from crop residues and manure in Japan were 6.1 Tg C year⁻¹ and 2.3 Tg C year⁻¹, of which 4.9 Tg C year⁻¹ and 1.9 Tg C year⁻¹, respectively, were applied to farmland soil. The average C application rate was 1.7 ± 1.6 Mg C ha farmland⁻¹ year⁻¹ and the proportion of manure was 23 ± 26%. One scenario that improved the allocation of manure and crop residue input to farmland soil increased the average C input to farmland soil to 1.8 ± 1.3 Mg C ha farmland⁻¹ year⁻¹. This agricultural C flow represented only a small percentage of the global warming potential of the whole of Japan. Thus, management of C resources in the agricultural sector should focus on the sustainable use of soil rather than the C sequestration potential of soil. To improve the C flow for areas with high C input, the transportation of manure to neighboring municipalities failed to reduce the excessive amount of manure since those areas are concentrated in only a few regions. Other measures were required to reduce environmental problems due to the over-supply of manure to farmland soils. For areas with low C input, the introduction of green manure, changes in cultivation methods, and land use type itself must be considered in relation to the individual C requirements specific to land use, soil type and climate conditions.     

Clothing-invariant gait identification using part-based clothing categorization and adaptive weight control

Variations in clothing alter an individual's appearance, making the problem of gait identification much more difficult. If the type of clothing differs between the gallery and a probe, certain parts of the silhouettes are likely to change and the ability to discriminate subjects decreases with respect to these parts. A part-based approach, therefore, has the potential of selecting the appropriate parts. This paper proposes a method for part-based gait identification in the light of substantial clothing variations. We divide the human body into eight sections, including four overlapping ones, since the larger parts have a higher discrimination capability, while the smaller parts are more likely to be unaffected by clothing variations. Furthermore, as there are certain clothes that are common to different parts, we present a categorization for items of clothing that groups similar clothes. Next, we exploit the discrimination capability as a matching weight for each part and control the weights adaptively based on the distribution of distances between the probe and all the galleries. The results of the experiments using our large-scale gait dataset with clothing variations show that the proposed method achieves far better performance than other approaches.     

4-O-Methyl Modifications of Glucuronic Acids in Xylans Are Indispensable for Substrate Discrimination by GH67 α-Glucuronidase from Bacillus halodurans C-125

A GH67 α-glucuronidase gene derived from Bacillus halodurans C-125 was expressed in E. coli to obtain a recombinant enzyme (BhGlcA67). Using the purified enzyme, the enzymatic properties and substrate specificities of the enzyme were investigated. BhGlcA67 showed maximum activity at pH 5.4 and 45 °C. When BhGlcA67 was incubated with birchwood, oat spelts, and cotton seed xylan, the enzyme did not release any glucuronic acid or 4-O-methyl-glucuronic acid from these substrates. BhGlcA67 acted only on 4-O-methyl-α-D-glucuronopyranosyl-(1→2)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranose (MeGlcA³Xyl₃), which has a glucuronic acid side chain with a 4-O-methyl group located at its non-reducing end, but did not on β-D-xylopyranosyl-(1→4)-[4-O-methyl-α-D-glucuronopyranosyl-(l→2)]-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-β-D-xylop- yranose (MeGlcA³Xyl₄) and α-D-glucuronopyranosyl-(l→2)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranose (GlcA³Xyl₃). The environment for recognizing the 4-O-methyl group of glucuronic acid was observed in all the crystal structures of reported GH67 glucuronidases, and the amino acids for discriminating the 4-O-methyl group of glucuronic acid were widely conserved in the primary sequences of the GH67 family, suggesting that the 4-O-methyl group is critical for the activities of the GH67 family.     

Interfacial Reaction between Zn-Al-Based High-Temperature Solders and Ni Substrate

The Zn-Al(-Cu) eutectic alloys (melting point 381°C) are candidates for use as Pb-free high-temperature solders as a substitute for Pb-based solders, which are suitable for severe working environments such as the engine room of hybrid vehicles equipped with an inverter system as well as a heat engine. In this study, the interfacial reaction between Zn-Al(-Cu) alloys and the Ni substrate during soldering, aging, and thermal cycling was investigated. Semiconductor chips and Ni substrates were soldered with Zn-Al(-Cu) alloys at various temperatures under a nitrogen atmosphere. The soldered assemblies were then heat-treated at 200°C and 300°C to examine the microstructural evolution at the soldered interface. The effect of severe thermal cycles between −40°C and 250°C in air on the microstructure and fracture behavior at the solder joint was investigated. Even after a 1000-cycle test, the thickness of the Al₃Ni₂ layer formed at the interface between the Zn-Al-based solder and the Ni substrate, which is responsible for the damage of the soldered assemblies, was quite small.     

Duplicated insertion mutation in the microtubule-associated protein Spag5 (astrin/MAP126) and defective proliferation of immature Sertoli cells in rat hypogonadic (hgn/hgn) testes

Male rats with hypogonadism (hgn/hgn) experience sterility from testicular dysplasia, which is controlled by a single recessive gene, hgn. The postnatal growth of the seminiferous tubules was severely affected. In this study, we localized the hgn locus to a 320 kb region on rat chromosome 10 and detected the insertion of a 25 bp duplication into the sixth exon of the sperm-associated antigen 5 (Spag5/astrin/MAP126) gene, which codes for a microtubule-associated protein. This mutation results in a truncated Spag5 protein lacking the primary spindle-targeting domain at the C terminus. Immunological staining with antibodies to markers for Sertoli and germ cells during the early postnatal period indicated that the abnormal mitosis with dispersed chromosomes in hgn/hgn testes occurs in proliferating Sertoli cells. Therefore, apoptotic Sertoli cell death would result from the disorganization of the spindle apparatus caused by defective Spag5. These findings suggested that the Spag5 is essential for testis development in rats and that the hgn/hgn rat is a unique animal model for studying the function of Spag5.     

Low-threshold distributed reflector laser consisting of wide and narrow wirelike active regions

We demonstrate a low-threshold distributed reflector laser, consisting of a distributed feedback section with wirelike active regions and a passive distributed Bragg reflector section with narrower ones, by utilizing the lateral quantum confinement effect. A threshold current under the room-temperature continuous-wave condition as low as 3.2 mA, which corresponds to a threshold current density of 290 A/cm/sup 2/, was obtained with the stripe width of 4.3 /spl mu/m and the active region length of 260 /spl mu/m. The differential quantum efficiency of 19% from the front facet, a high output ratio of 11 from the front facet to the rear facet, and a submode suppression ratio of 47 dB at a bias current 3.75 times the threshold were also achieved.     

A study of generator system selection for large wind turbine generator system

This paper focuses on selection of wind turbine generation systems that include generators, converters, and gears. We study three systems: a permanent magnet generator (PMG) system, a doubly‐fed generator (DFG) system, and a synchronous generator (SYG) system in terms of the system efficiencies and running costs. The system efficiencies and running costs are calculated by considering the relationship between wind power and wind conditions. According to these results, the one‐step gear PMG system is the best choice for a large wind turbine system. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(1): 51–57, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20506     

Complete Assignment of 1H and 13C NMR Spectra of Benz[a]Anthracene-7,12-dione and its Nitro Derivative

Benz[a]anthracene-7, 12-dione (1) was nitrated directly by nitric acid and a nitro-derivative (2) was obtained. Molecular orbital calculation predicted that the nitration reaction occurs in the C1 or C4 position of (1). To determine the position of the nitro group of (2), NMR chemical shifts were used. The absence of the chemical shift at δ9.7 in (2) clearly indicated that the nitro substituent issituated at the C1 position. The methodologies of FG-HOHAHA, FG-NOESY, FG-CH-COSY, and FG-HMBC were also used for detailed NMR spectral determination for their polycyclic aromatic ketons.     

Degradation of natural estrogen and identification of the metabolites produced by soil isolates of Rhodococcus sp. and Sphingomonas sp.

Five bacterial strains capable of utilizing 17β-estradiol (E2) and estrone (E1) were isolated from soil samples. Using their morphological and physiological features and 16S rDNA sequences, we classified these isolates into two groups: Group A (Rhodococcus sp. strains ED6, ED7, and ED10) and Group B (Sphingomonas sp. strains ED8 and ED9). All isolates used E2 and E1 as the sole carbon sources and showed high E1 and E2 degradation activities. In all strains, more than 50% of 0.8 mg of E1 or E2 was degraded in 4 mL of inorganic medium over 24 h, and 90% was degraded over 120 h. By incubating the resting ED8 cells with E2 and the meta-cleavage inhibitor 3-chlorocatechol, we identified two metabolites, 4-hydroxyestrone (4-OH-E1) and 4-hydroxyestradiol (4-OH-E2), and confirmed their identity using authentic chemicals. The 4-OH-E1 and 4-OH-E2 compounds were assumed to be intermediate metabolites formed before meta-cleavage, as they were not identified in culture without 3-chlorocatechol. Degradation of E2 by strain ED8 can be initiated by hydroxylation of the C-4 position, followed by meta-cleavage of the benzene ring. When strains ED8 degraded E2, we further identified hydroxy-E2, keto-E1 and -E2, and an additional degradation product via mass spectrometry. The presence of these compounds implied degradation through a second pathway initiated through an attack of the saturated ring.