A dinuclear Ni(mu-H)Ru complex derived from H2

Models of the active site in [NiFe]hydrogenase enzymes have proven challenging to prepare. We isolated a paramagnetic dinuclear nickel-ruthenium complex with a bridging hydrido ligand from the heterolytic cleavage of H2 by a dinuclear NiRu aqua complex in water under ambient conditions (20 degrees C and 1 atmosphere pressure). The structure of the hexacoordinate Ni(mu-H)Ru complex was unequivocally determined by neutron diffraction analysis, and it comes closest to an effective analog for the core structure of the proposed active form of the enzyme.     

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Contents     

alpha-Klotho as a regulator of calcium homeostasis

alpha-klotho was identified as a gene associated with premature aging-like phenotypes characterized by short lifespan. In mice, we found the molecular association of alpha-Klotho (alpha-Kl) and Na+,K+-adenosine triphosphatase (Na+,K+-ATPase) and provide evidence for an increase of abundance of Na+,K+-ATPase at the plasma membrane. Low concentrations of extracellular free calcium ([Ca2+]e) rapidly induce regulated parathyroid hormone (PTH) secretion in an alpha-Kl- and Na+,K+-ATPase-dependent manner. The increased Na+ gradient created by Na+,K+-ATPase activity might drive the transepithelial transport of Ca2+ in cooperation with ion channels and transporters in the choroid plexus and the kidney. Our findings reveal fundamental roles of alpha-Kl in the regulation of calcium metabolism.     

Phosphorus application reduces N2O emissions from tropical leguminous plantation soil when phosphorus uptake is occurring

We examined the effects of phosphorus (P) fertilization on N₂O emissions from an Acacia mangium plantation in Indonesia. We focused on the roles of microbial and plant root activities using a trenching method to prepare root-excluded and root-including plots. In root-excluded plots, P application did not change the amount of N₂O emissions. By contrast, in root-including plots, P application significantly reduced N₂O emissions (from 71.1?±?20.2 to 19.3?±?5.1 mg N m^?2 106 days^?1). Lower total P, Bray-2 P, and Bio-P (microbial P determined by chloroform fumigation extraction method) contents in the soils of root-including plots as compared to root-excluded plots a few days after P application shows that acacia trees absorbed P fertilizer rapidly. This rapid P uptake probably relieved the P limitation of acacia and might have consistently increased root N uptake. This interpretation is supported by lower inorganic N content in P-applied soils (the average of three sampling times is 8.9 and 11.3 μg N g soil^?1 in P-applied soils and soils without P application, respectively), which in turn decreased N₂O emissions. Our study suggests that P fertilizer suppresses N₂O emissions from tropical leguminous forest plantations.     

FC‐33 Expression of IL‐12 receptor β2 gene in atopic dogs

Atopic dermatitis (AD) is very common in dogs, but its pathogenesis is not yet fully understood. It has been suggested that a Th2‐dominant status may be associated with the occurrence of canine AD. IL‐12 is thought to be important for the differentiation of Th1 cells. The IL‐12 receptor β2 (IL‐12Rβ2) gene is considered to play a critical role in signal transduction and is attracting attention as one of the causative genes of AD in humans. The purpose of this study was to investigate the relationship between IL‐12Rβ2 gene expression and canine AD. The canine IL‐12Rβ2 gene was cloned by RT‐PCR and its nucleotide sequences were determined. Canine IL‐12Rβ2 showed 76.8% homology at the amino acid level with human IL‐12Rβ2, and its structural motifs were well conserved. cDNA with a 91 bp deletion including the transmembrane region was also cloned, which consequently produced a frame shift and an early stop codon. The deletion region corresponded to exon 14 of the human IL‐12Rβ2 gene on chromosome 1. The expression of deleted canine IL‐12Rβ2 mRNA in phytohemagglutinin‐stimulated peripheral blood mononuclear cells was examined in seven healthy dogs and 11 AD dogs. Both deleted and intact mRNAs were expressed at constant ratios in healthy and AD dogs. The results indicate that the deletion of the transmembrane region is not associated with the occurrence of AD, and that the expression of the deleted mRNA may be constitutive and produced by alternative splicing. Funding: Self‐funded.     

Anaerobic co-digestion of dairy manure and Japanese knotweed (Fallopia japonica) under thermophilic condition: Optimal ratio for biochemical methane production

Anaerobic co-digestion of animal manure and lignocellulosic biomass is a potent approach for sustainable biomethane production. Co-digestion of dairy manure (DM) and Japanese knotweed (JK), which was collected from a riverbank, was investigated at five different DM-to-JK mixing ratios (100:0, 90:10, 80:20, 60:40, and 0:100; wet weight basis) under thermophilic condition. The results showed that the methane yields obtain from the co-digestion of DM and JK were much higher than that obtained from JK alone (104 ml/gVS), which indicates the synergistic effect and the benefits of co-digesting JK with DM. The highest methane yield (232 ml/gVS) was obtained from the DM-to-JK ratio of 90:10, which was 14.9% and 123.1% higher than that from DM and JK alone, respectively. It also showed the highest synergistic effect (61 ml/gVS). However, further increase in JK ratios led to the decrease in methane yield and synergistic effect. Therefore, applying the co-digestion of DM and JK at a ratio of 90:10 is recommended for biomethane production.     

Morphological reproductive characteristics of testes and fertilization capacity of cryopreserved sperm after the Fukushima accident in raccoon (Procyon lotor)

Since the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, we have established an archive system of livestock and wild animals from the surrounding ex-evacuation zone. Wildlife within the alert zone have been exposed to low-dose-rate (LDR) radiation for a long continuous time. In this study, we analysed the morphological characteristics of the testes and in vitro fertilization (IVF) capacity of cryopreserved sperm of racoons from the ex-evacuation zone of the FDNPP accident. The radioactivity of caesium-137 (¹³⁷Cs) was measured by gamma-ray spectrometry, and the measured radioactivity concentration was 300–6,630 Bq/kg in the Fukushima raccoons. Notably, normal spermatogenesis was observed in the seminiferous tubules of the testes, with the germinal epithelium composed of a spermatogenic cell lineage with no evident ultrastructural alterations; freeze-thawing sperm penetration ability was confirmed using the interspecific zona pellucida-free mouse oocytes IVF assays. This study revealed that the chronic and LDR radiation exposure associated with the FDNPP accident had no adverse effect on the reproductive characteristics and functions of male raccoons.     

Performance of Pot-Grown Seedlings of the Dipterocarp Dryobalanops lanceolata with Controlled-Release Fertilizer after Transplantation to the Shifting Cultivation Land in Sarawak, Malaysia

In the present study, the focus was placed on the survival, growth, nutrient status, and ectomycorrhizal formation of pot-grown dipterocarps treated with a controlled-release fertilizer or a chemical fertilizer when transplanted to abandoned shifting cultivation land. Either a chemical fertilizer (CF) or a 700-day controlled-release fertilizer (CRF) had been applied to Dryobalanops lanceolata seedlings at the rates of 0, 2, 5, and 10 g fertilizers per pot in the nursery of the Forest Research Station Niah (FRSN), Miri, Sarawak, Malaysia. The seedlings were cultivated for 18 months in the nursery, and then transplanted to abandoned shifting cultivation land around the FRSN. At 16 months after transplantation, the plants in the CRF treatments showed a good performance in terms of growth and survival ability, because of the sufficient amounts of nutrients accumulated in plants with a sound shoot form and high photosynthetic activity at the nursery stage. On the other hand, many saplings in the CF treatments at the rates of 5 g and 10 g died in the field due to their spindly shoot form and low photosynthetic activity in the nursery, even though the saplings that survived showed on adequate growth. Therefore, the application of slow-release type CRF in the nursery was considered to be feasible and suitable for successful establishment of a dipterocarp plantation in the field. Ectomycorrhizal fungus present in the nursery would sustain and be correlated with P uptake of the saplings after transplantation.