Structure of thermal convection development based on inhomogeneous water surface cooling

The generation and development of thermal convection based on inhomogeneous water surface cooling were examined by hydraulic and numerical experiments to examine the characteristics of thermal convection in a closed water body with aquatic plants. A visualization experiment revealed the structural characteristics of a whirlpool when thermal convection was generated quantitatively by using PIV analysis. Then, a water temperature measurement experiment demonstrated that a steady cold water mass generated based on the heat flux transport from the water surface increases. This explained each of the three stages in the convection development process. Moreover, aquatic plants, which grow thickly on the water surface, cause not only vertical but also horizontal flows based on the density difference with the water surface that is not covered by plants, and thus change the development process of the convection cell.     

Stabilization of myosin by ionic compounds as affected by F-actin

ABSTRACT:   Suppressive effects of non-ionic (sorbitol, maltose, and trehalose) and ionic (Na-glutamate, Na-acetate, Na-sulfate, and ammonium sulfate) compounds on the thermal inactivation of myosin subframgent-1 (S-1) and myofibril Ca²⁺-ATPase were compared. All compounds suppressed S-1 denaturation. When myofibrils were used (at 0.1 M KCl), sugars and sugar alcohol (non-ionic compounds) suppressed denaturation similar to S-1, while Na-glutamate, Na-acetate, and Na-sulfate weakly suppressed them. Ammonium sulfate accelerated denaturation, but suppressed denaturation when heated in 2 M KCl, at which myosin lost protection by F-actin. It was thus concluded that ionic compounds affected the denaturation of myofibrils in two ways; suppression as established with S-1, and acceleration as a result of loss of protection by F-actin caused by increase in ionic strength.     

Suppressing effect of neocarrabiose 4-O-sulfate on thermal and freeze denaturation of myosin subfragment-1 and myofibrils

Suppressive effects of neocarrabiose 4-O-sulfate on the thermal and freeze denaturation of myosin subfragment-1 (S-1) and on myofibrils were investigated. The compound strongly suppressed the thermal denaturation of S-1. Its suppressive effect was greater than that of sorbitol and similar to that of maltose. However, it tended to accelerate the denaturation of myofibrils, suggesting a loss of protection by F-actin upon its addition. The compound suppressed the freeze denaturation of myofibrils and S-1. The effect was similar to that of sorbitol or maltose, and completely different from that of Na-sulfate. The compound solubilized myofibrils at concentrations similar to KCl. Therefore, it was concluded that neocarrabiose 4-O-sulfate behaved as an ionic salt in the thermal treatment process, whereas it behaved as a sugar in the frozen storage process.     

Fractionation of woody biomass with boiling aqueous acetic acid containing a small amount of mineral acid at atmospheric pressure: Reactivity of arylglycerol-β-aryl ethers in lignins with aqueous acetic acid containing H2SO4

To characterize the mechanism of the reaction of lignin with aqueous acetic acid (AW) containing a small amount of H₂SO₄, guaiacylglycerol--guaiacyl ether (GOG), and guaiacylglycerol--syringol ether (GOS) were refluxed in 90% AW with 0.28% H₂SO₄ for 0–120 min. Reaction products and their silylated derivatives were characterized by analytical methods such as gas chromatography-mass spectrometry and nuclear magnetic resonance. When the model compounds were allowed to react at boiling temperature for 0 min (heat-up time 30 min), most of their primary alcohol groups and some of their secondary alcohol groups were acetylated, but their phenolic groups were not. About 90% of GOG was degraded, polymerized, or both during boiling for at least 15 min, yielding guaiacol and isocoumaran compounds (GOG-e and GOG-f) in addition to homovanillin (II) as guaiacylvinyl alcohol (I) and other minor products. GOS yielded syringol, homovanillin (II), and a novel compound (V) together with unknown products but not the corresponding isocoumaran compounds.     

Myosin denaturation in “Burnt” Bluefin tuna meat

A quantitative conversion of tuna meat into muscle homogenate made it possible to study myosin denaturation in Bluefin tuna meat. Myosin denaturation was accessed by measuring Ca²⁺-ATPase activity, salt-solubility with and without Mg-ATP, monomeric myosin content, and amount of subfragment-1 (S-1) and rod produced by chymotryptic digestion. Commercially available tuna used in this study showed a pH around 5.4–5.7. Myosin in the meat lost the salt-solubility measured in the absence of Mg-ATP; however, such myosin showed full salt-solubility when released from actin in the presence of Mg-ATP. Incubation of tuna meat at 30 °C for up to 90 min caused obvious myosin denaturation. However, the tuna meat dialyzed against neutral pH buffer showed practically no myosin denaturation by the same heating. It was suggested that exposure to lowered pH to around 5.5 and increased temperature of 30 °C led myosin denaturation. Myosin denaturation in the “Burnt” Bluefin tuna sample was analyzed. A significant myosin denaturation was observed with the part showing the “Burning” symptom, the inner part of the tuna meat near the spine. Myosin in that part showed almost no Ca²⁺-ATPase activity, no salt-solubility even with Mg-ATP, no recovery of monomeric myosin, and almost no production of S-1 by chymotryptic digestion. However, myosin denaturation was not detectable for the meat taken from outer parts of the same tuna near the skin with normal appearance. It was demonstrated that “Burning” of tuna meat occurring in the deep part of the body is accompanied by myosin denaturation. The above results suggested that insufficient cooling of the deep part of body would be the reason for “Burning” of tuna meat.     

QTLs for phosphorus deficiency tolerance detected in upland NERICA varieties

Phosphorous (P) deficiency is a major yield limiting factor in rice (Oryza sativa L.) production. The interspecific New Rice for Africa (NERICA) varieties combine general stress tolerance from African cultivated rice (Oryza glaberrima Steud) with characteristics associated with high yield from O. sativa. However, little is known about their ability to tolerate P deficiency. Here, we examined the variation for tolerance to P deficiency among the 18 upland NERICAs and their parents in multi‐year field experiments. The good performance under P deficiency of the O. glaberrima parent CG 14 and some NERICAs suggested that these tolerant NERICAs contain loci associated with P deficiency tolerance inherited from CG 14. Additionally, four QTL clusters for P deficiency tolerance were detected on chromosomes 4, 6 and 11 using F₃ lines derived from the cross between the P deficiency tolerant variety NERICA10 and a Japonica‐type sensitive variety ‘Hitomebore’. These QTLs represent the first step in identifying stress tolerance genes from O. glaberrima that could subsequently be used to enhance P deficiency tolerance in O. sativa.     

A clinical case of severe anemia in a sheep coinfected with Mycoplasma ovis and 'Candidatus Mycoplasma haemovis' in Hokkaido, Japan

A 2-year-old East Friesian sheep imported from Australia exhibited severe anemia after contagious pustular dermatitis in Hokkaido, Japan. Hemoplasma infection was confirmed in blood smears. Both Mycoplasma ovis and 'Candidatus Mycoplasma haemovis' were detected by PCR and sequence analyses. In the epidemiological analysis, dual pathogens were detected in 6 of 12 (50.0%) sheep imported from Australia with the infected ewe at the same time, 1 of 5 (20.0%) sheep introduced from a domestic farm in Hokkaido, and in 1 of 16 (6.3%) sheep from an epidemiologically unrelated ranch. It is the first clinical case of sheep to confirm coinfection of these pathogens in Japan.     

Cdk2 activity is essential for the first to second meiosis transition in porcine oocytes

The meiotic progression of Xenopus oocytes has been suggested to depend on the activity of cyclin-dependent kinase 2 (Cdk2). We examined whether Cdk2 is involved in the regulation of mammalian oocyte meiosis by injecting porcine oocytes with anti-Cdk2 antibody. At first, the cross-reactivity of the anti-Cdk2 antibody with Cdc2 kinase was evaluated by immunoprecipitation and immunoblotting experiments using porcine granulosa cell extract, and no cross-reactivity with Cdc2 kinase was observed in the antibody used. In the anti-Cdk2 antibody-injected group, 50.7% of the oocytes were arrested in the second metaphase after 50 h of culture and this rate was significantly lower than those in the non-injected intact oocytes or the oocytes injected with mouse IgG (84.5% and 86.7%, respectively). Most of the other oocytes in the antibody-injected group formed a pronucleus without polar bodies or with only one polar body. The cyclin B1 amount in the antibody-injected and activated oocytes was dramatically decreased compared with that in the intact or mouse IgG-injected oocytes after 50 h of culture. These results suggest that Cdk2 is involved in the meiotic maturation of mammalian oocytes, and that the block of Cdk2 activity results in the failure of cyclin B1 accumulation and second meiosis induction.     

Whey acidic protein (WAP) depresses the proliferation of mouse (MMT) and human (MCF-7) mammary tumor cells

We previously reported that the enforced expression of exogenous whey acidic protein (WAP) significantly inhibited the proliferation of mouse mammary epithelial cells (HC11 and EpH4/H6 cells). This paper presents the first evidence that WAP also depresses the proliferation of mammary tumor cells from mouse (MMT cells) and human (MCF-7 cells). We established WAP-clonal MMT and MCF-7 cell lines, and confirmed the secretion of WAP from the WAP-clonal cells into culture medium. The enforced expression of WAP significantly inhibited the proliferation of MMT and MCF-7 cells in in vitro culture. FACScan analyses revealed that G0/G1 phase cell-cycle progression was disordered and elongated in the WAP-clonal MMT and MCF-7 cells compared to that of the control cells. The expression of cyclin D1 was significantly decreased in the WAP-clonal MMT and MCF-7 cells, suggesting that progression from the G1 to the S phase was delayed in the WAP-clonal cells. The present results indicate that WAP plays a negative regulatory role in the cell-cycle progression of mammary tumor cells via a paracrine mechanism.     

Change of fatty acid composition of the lumbar longissimus during the final stage of fattening in the Japanese Black cattle

Consideration of the shortened fattening period seems to be worthwhile for the realization of profitable beef production. In this study, change of fatty acid composition of the lumbar longissimus during the final stage of fattening was investigated in Japanese Black cattle. Each of 110 fattening animals was sampled three times: the initial two samples were taken by biopsy (25.7 months and 27.5 months on average) and the final one was from carcasses (29.9 months on average). Preliminary analysis indicated that removing muscle tissues from the constant body position of the living animals should be essential for sampling. Average monounsaturated fatty acids (MUFA) at three sampling points were 58.1%, 58.5% and 60.5%, and the differences of the third sampling with the first and second samplings were significant. Both in steers and heifers, MUFA also increased as the fattening stage proceeded, and MUFA of the heifers at all the sampling points were significantly higher than those of the steers. The increasing rate of MUFA rose from 0.21 percentage points (pp)/month at period 1 (from the first sampling to the second sampling) to 0.84 pp/month at period 2 (from the second sampling to the slaughter).