The electrical conductivity of post-perovskite in Earth's D' layer

Recent discovery of a phase transition from perovskite to post-perovskite suggests that the physical properties of Earth's lowermost mantle, called the D' layer, may be different from those of the overlying mantle. We report that the electrical conductivity of (Mg0.9Fe0.1)SiO3 post-perovskite is >10(2) siemens per meter and does not vary greatly with temperature at the conditions of the D' layer. A post-perovskite layer above the core-mantle boundary would, by electromagnetic coupling, enhance the exchange of angular momentum between the fluid core and the solid mantle, which can explain the observed changes in the length of a day on decadal time scales. Heterogeneity in the conductivity of the lowermost mantle is likely to depend on changes in chemistry of the boundary region, not fluctuations in temperature.     

Continuous plasma outflows from the edge of a solar active region as a possible source of solar wind

The Sun continuously expels a huge amount of ionized material into interplanetary space as the solar wind. Despite its influence on the heliospheric environment, the origin of the solar wind has yet to be well identified. In this paper, we report Hinode X-ray Telescope observations of a solar active region. At the edge of the active region, located adjacent to a coronal hole, a pattern of continuous outflow of soft-x-ray-emitting plasmas was identified emanating along apparently open magnetic field lines and into the upper corona. Estimates of temperature and density for the outflowing plasmas suggest a mass loss rate that amounts to approximately 1/4 of the total mass loss rate of the solar wind. These outflows may be indicative of one of the solar wind sources at the Sun.     

Structure of the hinge region of the mu heavy chain of human IgM immunoglobulins

The amino acid sequence around the central disulfide bridge linking the mu heavy chains of the human immunoglobulin M monomer is unlike that in immunoglobulin G. This hinge area contains one of the five oligosaccharides of the mu chain, is low in proline, and is the site of tryptic cleavage to yield Fabmicro and Fcmicro fragments.     

Protective role of ATP-sensitive potassium channels in hypoxia-induced generalized seizure

Adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channels are activated by various metabolic stresses, including hypoxia. The substantia nigra pars reticulata (SNr), the area with the highest expression of K(ATP) channels in the brain, plays a pivotal role in the control of seizures. Mutant mice lacking the Kir6.2 subunit of K(ATP) channels [knockout (KO) mice] were susceptible to generalized seizures after brief hypoxia. In normal mice, SNr neuron activity was inactivated during hypoxia by the opening of the postsynaptic K(ATP) channels, whereas in KO mice, the activity of these neurons was enhanced. K(ATP) channels exert a depressant effect on SNr neuronal activity during hypoxia and may be involved in the nigral protection mechanism against generalized seizures.     

Effects of fatty acid-free bovine serum albumin and fetal calf serum supplementing repair cultures on pre- and post-warm viability of biopsied bovine embryos produced in vitro

The objective of this study was to investigate the influence of fatty acid-free bovine serum albumin (BSA) or fetal calf serum (FCS) on the re-expansion of biopsied blastocysts and post-warm viability of subsequently vitrified embryos. Firstly, blastocysts produced in vitro were biopsied at Day 7 and cultured to allow repair in TCM199 with 0.3% BSA or 5% FCS for 24 h. The re-expansion rates and mean total numbers of cells of the re-expanded embryos after the repair culture with BSA were almost the same as that with FCS. Secondly, after biopsied embryos were similarly cultured for repair with BSA or FCS, re-expanded embryos were selected for vitrification. After warming and exposure to 0.5 M sucrose with 20% FCS in mPBS, the embryos were cultured in TCM199 with 5% FCS for 24 h. The re-expansion rate and mean total number of cells in re-expanded blastocysts in the BSA treatment group (97.4 +/- 2.9% and 106 +/- 42) was significantly higher than that in the FCS treatment group (51.6 +/- 9.1% and 61 +/- 38), respectively (P<0.05 and P<0.01). In conclusion, both FCS and BSA supplementation can be useful for repairing cultures of bovine biopsied blastocysts; but, compared with BSA supplementation, FCS supplementation during repair culture reduces the post-warm viability of biopsied and subsequently vitrified embryos.     

Analysis of antibody response by temperature-sensitive measles vaccine strain in the cotton rat model

Measles virus (MeV) vaccine strain, AIK-C, is temperature sensitive (ts), which is thought to be associated with attenuation of virus pathogenicity. In this study, replication and antibody response were examined in cotton rats using viruses carrying different forms of the P gene, which is responsible for the ts phenotype of strain AIK-C and its parental Edmonston strain. When cotton rats were inoculated intranasally, ts viruses neither replicated in lungs, nor reproducibly generated an antibody response. When inoculated intramusculary (i.m.), however, ts strains raised an antibody titer in all animals. This response was not observed when ultraviolet-inactivated virus was used. ts virus, inoculated i.m., was recovered from cotton rat drainage lymph nodes. These results suggest that ts virus, inoculated i.m., could replicate in the cotton rat, presumably at the superficial lymph node, and induce an antibody response. Therefore, cotton rats can serve as a small-animal model for investigating immune responses to safer ts vaccine, as well as recombinant vaccine using AIK-C as a vector for protection against other infectious agents.     

Occurrence and distribution of cis-7-icosenoic acid in the lipids of Japanese marine fish,shellfish, and crustaceans

This article reports the concentration and composition of the isomers of cis-icosenoic acid (20:1) in the fatty acids of various species of Japanese marine animals. The main purpose of this study is to reveal the distribution of a positional isomer, cis-7-20:1 (c7-20:1), in marine animals. Because this isomer overlaps with the c9-20:1 isomer in gas chromatography (GC) on the commonly used polar capillary columns, less information is available on its occurrence and distribution. In this study, the monounsaturated fatty acids isolated by argentation thin-layer chromatography were analyzed by GC using a highly polar capillary column, SLB-IL111 (100 m long), with the highest polarity among the commercially available GC columns. A clear separation between the c7-20:1 and c9-20:1 isomers enabled the analysis of all the isomers of 20:1 present in marine animals. The results confirmed that the c7 isomer was a minor component in the 20:1 in the pelagic fish, which is rich in the c9 and/or c11 isomers as reported previously. In contrast, the c7 isomer was one of the major isomers in flatfish, shellfish, crabs, and brittle stars. In these samples, the c13 isomer also occurred at higher concentrations rather than the c9 isomer. Because such a specific pattern of the 20:1 positional isomers was generally observed in both benthic fish and its dietary animals, the c7 isomer in the benthic fish probably originated from its diet. These marine animals are used as food in Japan, and therefore the c7-20:1 isomer is consumed by humans.     

Optimization of the supplemental essential amino acids to a fish meal-free diet based on fermented soybean meal for rainbow trout <Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>

To minimize the supplemental essential amino acids (EAAs) to a fish meal-free diet for rainbow trout Oncorhynchus mykiss, four types of fish meal-free diets and a control fish meal-based diet were fed to triplicate groups of trout (initial BW, 16 g) for 10 weeks. Two fish meal-free diets based on a fermented and an unfermented soybean meal were unsupplemented with EAAs (diet FSBM and SBM), and two fish meal-free diets based on the fermented soybean meal were supplemented with a combination of lysine and methionine (diet F + ML) and all EAAs (diet F + All), the EAA contents of which were lower than those of the control diet (diet FM). Although physiological conditions such as the biliary bile acid status and morphological features of fish fed diet FSBM were improved and similar to those of fish fed diet FM, the growth performance was not significantly different (P > 0.05) from fish fed diet SBM. The growth performances and whole body protein contents of fish fed F + ML and F + All diets were similarly improved compared to fish fed diet FSBM. These findings indicate that supplementation of lysine and methionine to a fermented soybean meal-based fish meal-free diet is enough to maximize the amino acid utilization of the diet.     

First record of wild ephyrae of the giant jellyfish Nemopilema nomurai

To understand the causes and to control harmful blooms of the giant Nomura??s jellyfish Nemopilema nomurai, it is essential to study the seed population (benthic polyps) and its environment. To locate the habitat of polyps, the first step is to find ephyrae shortly after detachment from polyps. We found five ephyrae of N. nomurai of 1?C2?mm diameter for the first time from plankton samples collected at two sites, one specimen in the northwestern East China Sea (32°12.3??N, 123°12??E) and the other four specimens in the Yellow Sea (34°05.8??N, 121°50.0??E), on 22 and 26 May 2011. From the developmental state and water temperature of ca. 16?°C at the sampling stations, the collected ephyrae were estimated to have detached from polyps in early May of the year. Considering the increase of water temperature which induces strobilation and the direction of transport in the northwestern East China Sea and in the Yellow Sea, the locality of the seed polyps of the present specimens is probably the sea-floor close to the Changjiang River mouth and along the coast of Jiangsu Province.