Elucidation of the neurological effects of clothianidin exposure at the no-observed-adverse-effect level (NOAEL) using two-photon microscopy in vivo imaging

Neonicotinoid pesticides (NNs) cause behavioral abnormalities in mammals, raising concerns about their effects on neural circuit activity. We herein examined the neurological effects of the NN clothianidin (CLO) by in vivo Ca²⁺ imaging using two-photon microscopy. Mice were fed the no-observed-adverse-effect-level (NOAEL) dose of CLO for 2 weeks and their neuronal activity in the primary somatosensory cortex (S1) was observed weekly for 2 weeks. CLO exposure caused a sustained influx of Ca²⁺ in neurons in the S1 2/3 layers, indicating hyperactivation of neurons. In addition, microarray gene expression analysis suggested the induction of neuroinflammation and changes in synaptic activity. These results demonstrate that exposure to the NOAEL dose of CLO can overactivate neurons and disrupt neuronal homeostasis.     

Engineered interface of magnetic oxides

Interface-selective probing of magnetism is a key issue for the design and realization of spin-electronic junction devices. Here, magnetization-induced second-harmonic generation was used to probe the local magnetic properties at the interface of the perovskite ferromagnet La(0.6)Sr(0.4)MnO3 with nonmagnetic insulating layers, as used in spin-tunnel junctions. We show that by grading the doping profile on an atomic scale at the interface, robust ferromagnetism can be realized around room temperature. The results should lead to improvements in the performance of spin-tunnel junctions.     

The anomalous Hall effect and magnetic monopoles in momentum space

Efforts to find the magnetic monopole in real space have been made in cosmic rays and in particle accelerators, but there has not yet been any firm evidence for its existence because of its very heavy mass, approximately 10(16) giga-electron volts. We show that the magnetic monopole can appear in the crystal momentum space of solids in the accessible low-energy region (approximately 0.1 to 1 electron volts) in the context of the anomalous Hall effect. We report experimental results together with first-principles calculations on the ferromagnetic crystal SrRuO3 that provide evidence for the magnetic monopole in the crystal momentum space.     

Current status of freshwater prawn culture in Vietnam and the development and transfer of seed production technology

ABSTRACT:   In Vietnam, the giant freshwater prawn Macrobrachium rosenbergii is becoming an increasingly important targeted species, as its culture, especially in rice fields, is considered to have the potential to raise income among impoverished farmers. The production of M. rosenbergii based on aquaculture reached over 10 000 tons per year in 2002, having increased from about 2500 tons since the 1990s. Until recently, lack of a stable supply of seed had been an important obstacle to the further expansion and development of M. rosenbergii culture, but cumulative research on larval rearing, especially in the 1990s, has led to the development of new seed production technology based on the 'modified stagnant green water system'. Following its dissemination by the efforts of provincial authorities, hatchery operators, and farmers, the freshwater prawn seed production industry developed rapidly in the Mekong Delta with over 90 hatcheries producing 76.5 million postlarvae in 2003. This is considered to have affected the expansion of rice–prawn farming in the Mekong Delta, leading to increased aquacultural production in the region. This paper reviews the current status of freshwater prawn culture in Vietnam and background history, and presents a socioeconomic evaluation of seed production technology implementation.     

Hormone injections enhance the tolerance of land-locked ayu spermatozoa to cryopreservation

We evaluated the effects of maturation-stimulating hormones on the post-thaw motility of land-locked form ayu ( Plecoglossus altivelis ) spermatozoa. Male ayu were administered three intraperitoneal injections of either salmon pituitary extract (SPE; 0.2 or 0.6 mg g⁻¹ BW day⁻¹) or of 17, 20β-dihydroxy-4-pregnen-3-one (DHP; 2 or 10 μg g⁻¹ BW day⁻¹), the maturation-inducing steroid (MIS) in ayu. Before cryopreservation, the motility of spermatozoa of the SPE- and DHP-treated groups was significantly higher than that of the control group. Similarly, the comparative post-thaw motility (presented as a percentage of the motility obtained before cryopreservation) was significantly higher in the SPE group than in the control; however, there was no significant difference between the DHP group and the control. The effect of SPE and DHP on pre- and post-cryopreservation motility was not dose dependent. Our results suggest that the hormone(s) present in salmon pituitary are effective in enhancing the tolerance of ayu sperm cells to cryopreservation and that the MIS (DHP) is not involved in this process.     

Identification of angiotensin I-converting enzyme inhibitory peptides derived from salmon muscle and their antihypertensive effect

ABSTRACT:   The salmon peptide digested from salmon muscle showed a strong inhibitory activity against the angiotensin I-converting enzyme (ACE). The antihypertensive effect of the salmon peptide on spontaneously hypertensive rats (SHR) was examined. After the single intravenous administration of the salmon peptide at a dose of 30 mg/kg body weight, the systolic blood pressure (SBP) was significantly reduced against the control. Further, a double-blind, placebo-controlled, parallel-group study determined the efficacy of the salmon peptide in mild hypertensive subjects. The SBP, after a 1.0 g of salmon peptide intake, was significantly reduced at 4 weeks after the intake, and 2 weeks after the intake finished, compared to the value before ingestion. Bioassay-guided separation of the salmon peptide, using a combination of column chromatographic techniques, led to the identification of 20 active di- and tri-peptides, including Ile-Val-Phe and Phe-Ile-Ala as two new ACE inhibitory tripeptides. Ile-Trp had the strongest ACE inhibitory activity (IC₅₀ = 1.2 μM) in vitro , and contributed 5.2% to the total ACE inhibitory activity. The salmon peptide and Ile-Trp showed a digestive resistance by in vitro assay, which mimicked the digestive organ, and had no affinity for factors related to blood pressure regulation, except for the ACE inhibitory activity.     

Effects of Integrated Organic and Inorganic Fertilizers on Yield and Growth Parameters of Rice Varieties

We investigated the effects of integrated organic and inorganic fertilizers on the growth and yield of indica rice variety Manawthukha and japonica rice variety Genkitsukushi. In a split-plot design, the two rice varieties were assigned as main plot factors, and the integrated treatments were the subplot factors, including no-N fertilizer(N_0), 50% chemical fertilizer(CF)(CF_(50)), 100% CF(CF100), 50% CF + 50% poultry manure(PM)(CF_(50)PM_(50)), 50% CF + 50% cow manure(CM)(CF_(50)CM_(50)), and 50% CF + 50% compost(CP)(CF_(50)CP_(50)). CF100 was equivalent to N at 85 kg/hm~2. Manure was applied based on the estimated mineralizable nitrogen(EMN) level, which is dependent on total N(%) of each manure type. Manawthukha rice plants were taller with higher tiller number and dry matter content. However, higher soil-plant analysis development(SPAD) values were measured in Genkitsukushi throughout the crop growth period, resulting in higher seed-setting rate(%) and greater yield. At the same N level, CF_(50)PM_(50) application in both rice varieties resulted in higher SPAD values, plant height and tiller number than CF_(100). CF_(50)PM_(50) containing total N more than 4% supplied synchronized N for the demands of the rice plants, resulting in maximum dry matter, yield and yield components. CF_(50)CM_(50) and CF_(50)CP_(50) treatments containing total N less than 4% resulted in lower yields which were similar to CF_(100). These results indicated that integrating organic and inorganic fertilizers enhanced growth parameters and yields of Manawthukha and Genkitsukushi, while reducing the dose of chemical fertilizer.     

Two histone marks establish the inner centromere and chromosome bi-orientation

For proper partitioning of chromosomes in mitosis, the chromosomal passenger complex (CPC) including Aurora B and survivin must be localized at the center of paired kinetochores, at the site called the inner centromere. It is largely unknown what defines the inner centromere and how the CPC is targeted to this site. Here, we show that the phosphorylation of histone H3-threonine 3 (H3-pT3) mediated by Haspin cooperates with Bub1-mediated histone 2A-serine 121 (H2A-S121) phosphorylation in targeting the CPC to the inner centromere in fission yeast and human cells. H3-pT3 promotes nucleosome binding of survivin, whereas phosphorylated H2A-S121 facilitates the binding of shugoshin, the centromeric CPC adaptor. Haspin colocalizes with cohesin by associating with Pds5, whereas Bub1 localizes at kinetochores. Thus, the inner centromere is defined by intersection of two histone kinases.     

Short-term evaluation of oxygen transfer from rice (Oryza sativa) to mixed planted drought-adapted upland crops under hydroponic culture

Mixed cropping is a cultivation method widely practiced in tropical regions. The newly developed close mixed planting technique mitigates the flood stress of drought-adapted upland cereal species by co-growing rice (Oryza sativa) plants under field flood conditions. We tested the hypothesis that O₂ was transferred from rice to upland crops using the model system of hydroponic culture. To confirm the hypothesis, the phenomena of O₂ absorption and release by plants were evaluated in a water culture condition without soil. Experiments were conducted in a climate chamber to estimate the amount of O₂ released from the roots of rice and pearl millet (Pennisetum glaucum) under both O₂-rich (20.0 ± .0% conc. in phase I) and O₂-free dark (.8 ± .0% conc. in phase II) conditions. The total O₂ change (between the two phases) in a single planting of rice and pearl millet was significantly higher than that of the mixed planting of rice and pearl millet, which indicated that O₂ was transferred from rice to pearl millet under a water culture condition. The result indicated that approximately 7 μM O₂ g fresh root weight^?1 h^?1 was transferred between the two plant species. O₂ transfer was confirmed between the two plant species in a mix cultured in water, implying its contribution to the phenomenon that improved the physiological status of drought-adapted upland crops under field flood conditions.