Dielectric study of heat-denatured ovalbumin in aqueous solution by time domain reflectometry method

The dielectric behavior of native and heat-denatured ovalbumins (OVAs) from three avian species in aqueous solution was examined over a frequency range of 100 kHz to 20 GHz, using the time domain reflectometry (TDR) method. For the native OVA solutions, three kinds of relaxation processes were observed at around 10 MHz, 100 MHz, and 20 GHz, respectively; these could be assigned to the overall rotation of protein molecules, the reorientations of the bound water, and the free water molecules, respectively. For the heat-denatured samples, three relaxation processes were also observed. However, the relaxation process at approximately 100 MHz originated via a different mechanism other than the reorientation of bound water, namely, the micro-Brownian motion of peptide chains of heat-denatured protein. From the observed relaxation process at approximately 100 MHz, the relaxation strength of heat-denatured OVA solution for duck was higher than that of OVA solutions for hen and guinea fowl and showed the pH dependency from pH 7.0 to 8.0 for OVAs obtained from all three species. Furthermore, the results demonstrated that the relaxation strength was closely related to surface hydrophobicity of protein molecules and gel rheological properties. It was suggested that the difference in the surface hydrophobicity of protein influenced the dielectric behavior of water around denatured protein, whereas the dielectric behavior of denatured protein could be an indication of the gel rheological properties. Such studies can aid in the understanding of the different network structures of OVA gels from three avian species.     

Lactobacillus ingluviei C37 from chicken inhibits inflammation in LPS‐stimulated mouse macrophages

Probiotics are growing alternatives to antibiotics, and can contribute to the prevention and treatment of diseases and enhance livestock production. Lactobacillus (L.) ingluviei is a novel probiotic species with growth‐enhancement effects; however, this species remains poorly understood, and there have been (to our knowledge) no studies focusing on its immunological effects. Here, we isolated L. ingluviei C37 (LIC37) from chicken and evaluated the bacterium's immunomodulatory properties to explore its probiotic potential. Real‐time quantitative PCR and ELISA showed that in vitro exposure of inflammation‐stimulated mouse peritoneal macrophages to heat‐killed LIC37 led to decreases in tumor necrosis factor‐α and interleukin (IL)‐6 levels and an increase in IL‐10. These findings suggested that LIC37 exerts anti‐inflammatory effects by modulating cytokine profiles. This species may be an attractive probiotic bacterial strain for use in animal production.     

Differences in leafminer (Phyllonorycter, Gracillariidae, Lepidoptera) and aphid (Tuberculatus, Aphididae, Hemiptera) composition among Quercusdentata, Q. crispula, Q. serrata, and their hybrids

Leafminer (Phyllonorycter, Gracillariidae, Lepidoptera) and aphid (Tuberculatus, Aphididae, Hemiptera) composition were studied in three deciduous oak species, Quercus dentata, Q. crispula, and Q. serrata, and their hybrids in Tomakomai Experimental Forest of Hokkaido University, Hokkaido, northern Japan. Identification of trees in this forest was done mainly on the basis of discriminant analysis on leaf morphology with reference to trees in pure Q. dentata and Q. crispula stands and a Q. serrata stand mixed with Q. crispula. The results suggested that hybridization occurred in all combinations (i.e. Q. dentata–Q. crispula, Q. crispula–Q. serrata, and Q. serrata–Q. dentata) and the frequency of hybrids was approximately 10%. The composition of Phyllonorycter and Tuberculatus species differed between Q. dentata and Q. crispula or Q. serrata, but did not differ between Q. crispula and Q. serrata. Thus, Q. dentata could differ from Q. crispula and Q. serrata in chemical properties that determine herbivore host selection, survival, and performance, possibly reflecting eco-physiological differences or phylogenetic distances. The study insects were divided into three groups: species specialized to Q. dentata (three Phyllonorycter and one Tuberculatus species), those to Q. crispula and Q. serrata (six Phyllonorycter and two Tuberculatus species), and a species collected at least from Q. dentata and Q. crispula (one Tuberculatus species). Putative hybrid trees of Q. dentata and Q. crispula harbored both Q. dentata-specific and Q. crispula-specific insects.     

Superelastic effect in polycrystalline ferrous alloys

In superelastic alloys, large deformation can revert to a memorized shape after removing the stress. However, the stress increases with increasing temperature, which limits the practical use over a wide temperature range. Polycrystalline Fe-Mn-Al-Ni shape memory alloys show a small temperature dependence of the superelastic stress because of a small transformation entropy change brought about by a magnetic contribution to the Gibbs energies. For one alloy composition, the superelastic stress varies by 0.53 megapascal/°C over a temperature range from -196 to 240°C.     

Application of shallow water equations to analyze runoff processes in hilly farmlands

Analysis of runoff processes in farmlands during storm events in particular is an important engineering topic. The shallow water equations describing the physical conservation laws are attractive tools for understanding motion of surface water. A numerical model is developed to reproduce surface water flows during storm events, using the finite element method and the finite volume method applied to the one-dimensional shallow water equations. The numerical model has the advantage of dealing with transcritical flows, wet, and dry processes, irregular channel bed slopes, and channel junctions involving multiply connected networks. Standard numerical tests demonstrated some of these features. Runoff processes from farmlands in a Japanese hilly area is analyzed with the numerical model coupled with another runoff model of black-box type. Parameters of the models are calibrated and validated using observed series of rainfall and runoff discharge data. Simulated results included submergence of hydraulic jumps and flood storage in farming plots, which are very informative in terms of assessing diverse functions of the farmlands.     

Groundwater flow and transport and potential sources of groundwater nitrates in the Ryukyu Limestone as a mixed flow aquifer in Okinawa Island, Japan

We investigated the groundwater flow and the transport and potential source of groundwater nitrates in the typical karst setting of the Ryukyu Limestone aquifer in the southern part of Okinawa Island, Japan. Analysis of groundwater hydrographs indicated that this is a ??mixed flow?? aquifer with the coexistence of slow diffuse flow in the matrices and rapid conduit flow in the caves and caverns. This relationship is indicated by the travel time of groundwater flow: 70?days in the matrices of the aquifer and 6?days through the caves and caverns. The conduit flow system was also confirmed by the distribution of relatively low concentrations of ²²²Rn near caverns. The sampling sites were categorized into upland field (UF) type and residential area (RA) type according to the land-use ratio on the upstream side with a 600-m influential radius, and cave and cavern (CC) type according to the hydrogeologic setting near two large caverns, even though the CC type should be categorized as the UF type from the viewpoint of land use. Cross plots of NO₃-N versus SO₄ ^2? showed that the predominant source of UF groundwater nitrates was chemical fertilizer. A difference was observed in average ??¹⁵N values between UF (8.9??) and RA (10.0??). On the other hand, the average ??¹⁵N value for CC (10.5??) was similar to that for RA, indicating that CC nitrates were not related to the surrounding land use. This phenomenon is considered as evidence that CC groundwater nitrates were carried by rapid groundwater flow through caves and caverns from residential areas located higher upstream compared to the influential areas. According to previous studies, animal and human waste was considered the predominant sources of RA and CC groundwater nitrogen. The contribution ratio of chemical fertilizer (R _CF) was calculated using mass balance equations under assumed predictability. There was a relatively high correlation between the rate of upland areas and of residential areas and R _CF. Average R _CF for UF, RA and CC was 41, 27, and 25%, respectively.     

Efficient bioethanol production from water hyacinth Eichhornia crassipes by both preparation of the saccharified solution and selection of fermenting yeasts

Although water hyacinth is an adventive aquatic plant that threatens the Japanese ecosystem, its high growth rate may be a benefit in terms of its potential as a raw material for the production of bioethanol. In our study, water hyacinth was saccharified with 3?% (v/v) sulfuric acid and subjected to cellulase treatments to determine optimum bioethanol production conditions. The original saccharified solution yielded both glucose at 5.3?±?0.2?g/l and reducing sugars at 9.7?±?0.1?g/l. Concentration of the saccharified solution under vacuum at 70?°C yielded both glucose at 21.5?±?2.9?g/l and reducing sugars at 33.3?±?2.1?g/l. An aquatic yeast Saccharomyces cerevisiae TY2 produced ethanol at 9.6?±?1.1?g/l from the concentrated saccharified solution. In comparison, Ogawa et al. (Afr J Microbiol Res 2:110?C113, 2008) reported that this yeast produced 0.90?g/l and that the production of bioethanol was about 11.2-fold lower than that obtained in our study. These results suggest that refinement of the saccharification process and application of the selected yeast could improve the efficiency of obtaining bioethanol from the water hyacinth.