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.     

Prediction of enteric methane emissions from lactating cows using methane to carbon dioxide ratio in the breath

The aim of this study was to develop prediction equations for methane (CH₄) emissions from lactating cows using the CH₄/carbon dioxide (CO₂) ratio in the breath measured in the automatic milking system (AMS) and to evaluate the predicted values and factors affecting the CH₄/CO₂ ratio. The model development was conducted using a dataset determined in respiration chambers or head boxes (n = 121). Then, gas measurements in the AMS as well as in the head box were carried out with six lactating cows fed one of three different levels of neutral detergent fiber (NDF) content, following a 3 × 3 Latin square experimental design. The obtained equation that is suitable for practical use on farms to predict CH₄ was CH₄ (L/day) = −507 + 0.536 live weight (kg) + 8.76 energy-corrected milk (kg/day) + 5,029 CH₄/CO₂ (adjusted R² = 0.83; root mean square error = 40.8 L/day). Results showed that the predicted values correlated positively with the observed values, the determined CH₄/CO₂ ratio increased with increasing dietary NDF content, and the detected eructation rate was in the normal range. On the other hand, the CH₄/CO₂ ratio was affected by the time interval between measurement and last eating before the measurement.     

Urbanization and its implications for avian aggression: a case study of urban black kites (Milvus migrans) along Sagami Bay in Japan

Urbanization has caused countless changes in the lives, behaviors, and community structures of wild animals. Habitat loss in urban areas has led to the proliferation of certain species over others; in the case of birds, frugivores and certain predators can be found in abundance in cities. These birds, however, occasionally show novel behaviors that can cause stress within human-wildlife interactions. The black kite, Milvus migrans, for example, has displayed a tendency to attack humans for their food in certain urban areas in Japan. In order to determine how habitat availability and land-use types affected these aggressive tendencies, field observations were combined with GIS analysis of five locations along Sagami Bay in Japan. The following locations were assessed according to the amount of each land-use type present and the aggressive tendencies of each location’s black kite population: Enoshima, Fujisawa; Kamakura Beach, Kamakura; Zushi Beach, Zushi; Oiso Beach, Oiso; and Iwa Beach, Manazuru. The aggression of each population, designated by the log of the aggression index, was found to be significantly affected by the amount of forest area per black kite, the amount of non-rice-paddy agricultural area per black kite, and the season. Thus, aggression was higher amongst populations with less forested or agricultural area within their foraging zones, and aggression increased during spring, which is the breeding season.     

Molecular cloning, tissue expression, and subcellular localization of porcine peptidoglycan recognition proteins 3 and 4

Peptidoglycan recognition proteins (PGRPs) are innate immune molecules that are present in most invertebrates and vertebrates. Mammals have four PGRPs, PGLYRP1-4. In the present study, we cloned the cDNAs encoding porcine PGLYRP3 and 4 from the esophagus of adult swine. The length of the complete open reading frames of porcine PGLYRP3 and 4 are identical and contain 1125bp encoding 374 amino acid residues. The amino acid sequences of these two proteins were more similar to their human orthologs (78.9% [PGLYRP3] and 73.9% [PGLYRP4]) than to their mouse orthologs (71.3% [PGLYRP3] and 67.9% [PGLYRP4]). Expression analysis revealed that both PGLYRP3 and 4 were more strongly expressed in digestive tract, especially the esophagus, than in immune organs such as spleen or mesenteric lymph nodes in both newborn and adult swine. To analyze the subcellular distribution of porcine PGLYRP1-4, we constructed transfectant cell lines. Western blot and flow cytometric analyses revealed that porcine PGLYRP3 and 4 are not only secreted, but also expressed on the cell surface, unlike PGLYRP1 and 2. These results should help contribute to the understanding of PGLYRP3- and 4-mediated immune responses via their recognition of intestinal microorganisms in newborn and adult swine.     

Model studies on volatile release from different semisolid fat blends correlated with changes in sensory perception

The effect of dispersed aqueous droplets in water-in-oil (W/O)-emulsion semisolid fats on aroma release and sensory perception was investigated on margarine models where model aroma substances were added. Aroma release from W/O-emulsion fat blends and bulk fat blends with added monoglycerides combining different fatty acids of various short-chain free fatty acids, methylketones, esters, and lactones were measured using headspace solid phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS), and their perception profiles were evaluated by sensory analysis. The presence of aqueous phase in a fat blend significantly reduced the headspace concentrations of butanoic acid and hexanoic acid, and also decreased the perceived intensity of total aroma and cheesy aroma. The aroma release of methylketones, esters, and lactones from the W/O-emulsion fat blends increased with increasing carbon chain length of the volatile molecules. The intensity of aroma perception in a W/O-emulsion fat blend depended on the melting point of the fatty acids (oleic, palmitic, stearic, and behenic) of the monoglyceride used as an emulsifier. Thus, aroma release from a W/O-emulsion semisolid fat blend was influenced by interactions between aroma volatiles and the dispersed aqueous droplets and by their viscoelastic properties.     

Nitrate content and induction of NADH nitrate reductase in cultured rice cells

The nitrate content of cultured rice cells grown in liquid R-2 medium containing 40 mM nitrate increased rapidly and reached a maximum 6 hr after inoculation. After about 6-hr lag period, NADH nitrate reductase activity increased rapidly to the 24th hr. Promotive effects on the nitrate accumulation and the induction of NADH nitrate reductase were found by the addition of 5 mM ammonium into the medium. Nitrate content increased exponentially as a function of increasing external nitrate concentration between 0 and 80 mM. The NADH nitrate reductase activity also increased from 0 to 40 mM of nitrate media, but leveled off between 40 and 80 mM.

A high level of nitrate content was detected in the cells grown in 10 or 40 mM of nitrate medium without sucrose for 48 hr, suggesting that sucrose in the medium may have no effect on the nitrate accumulation in the early growth period.     

Improvement of the NH2OH-HCl-HOAc method for extracting manganese and iron oxides in Japanese Andisols and other soil types in Japan

Abstract

We evaluated the validity of Tessier’s method as applied to the extraction of manganese (Mn) and iron (Fe) oxides in Japanese Andisols and other soil types in Japan. Using the original Tessier’s extractant mixture, 0.04 mol L^?1 hydroxylamine hydrochloride in 25% acetic acid (0.04 mol L^–1 NH₂OH-HCl in 25% HOAc), we found that substantial amounts of short-range-ordered Fe oxides were not extracted from allophanic Andisol samples and that considerable amounts of total Fe oxides were not extracted from all soil types. Relatively high extraction pH and large amounts of short-range-ordered Fe oxides in the Andisol samples might be responsible for incomplete extraction. Stoichiometric calculation indicated that the concentration of NH₂OH-HCl might be insufficient for complete extraction of Fe oxides. The extracted amounts of Mn and Fe increased with increasing concentration of NH₂OH-HCl in the extractant, and most of the Mn and Fe oxides in the soil samples, including samples with as much as 5.6% Fe, were extracted with 0.6 mol L^–1 NH₂OH–HCl in 25% HOAc. As judged from the simultaneous dissolution of aluminum (Al) and silicon (Si) minerals, extraction selectivity of Fe oxides with 0.6 mol L^–1 NH₂OH-HCl in 25% HOAc was comparable to that of the original Tessier’s method and better than that of a modified Community Bureau of Reference (BCR) sequential extraction procedure or a method using an extractant consisting of a mixture of oxalate and ascorbate, especially for Andisol samples.     

Comparative analysis of the relationship between Cs and K in soil and plant parts toward control of Cs accumulation in rice

The effect of soil exchangeable potassium (K) and cesium (Cs) levels on Cs uptake and accumulation in different parts of rice (Oryza sativa L.) plants were examined using paddy soils with diverse exchangeable K and Cs in pot experiments. Aboveground Cs uptake decreased with higher exchangeable K and was linearly correlated with exchangeable Cs/K ratios, indicating competitive absorption of these elements by roots. Variation in Cs concentration in brown rice among soils was also related to the exchangeable Cs/K ratio. The exchangeable Cs/K ratio was positively reflected in the Cs/K concentration ratio in each plant part, with a specific slope, suggesting that Cs transport was coordinated with K transport and that there were regulated discriminations of Cs against K in the translocation process among parts. The Cs/K ratio was higher in brown rice and dead leaves than in active leaves, stems and husks. The distribution of Cs accumulation in brown rice was 14.5% on average, but it was variable and negatively related to K concentration in the stem. The Cs distribution in aboveground plant parts also decreased with higher K concentration in the root. These results imply the importance of the competitiveness with K in the root absorption and translocation of Cs within the plant. Based on the observed relationship between Cs and K, effective K management and other measures to control Cs accumulation in plant parts are discussed.     

Occurrence probabilities of tree cavities classified by entrance width and internal dimensions in hardwood forests in Hokkaido, Japan

To estimate cavity availability for species with diverse cavity requirements, we recorded cavities in eight deciduous hardwood forests in Hokkaido, Japan, and classified them into two categories based on their entrance width (small, 2.5–5 cm; large, ≥5 cm). In two of the forests, we inspected cavity interiors and classified cavities into three further categories based on their internal dimensions (shallow, moderate, and deep). We then estimated the occurrence probabilities of cavities of different sizes at the individual-tree level. Although the cumulative occurrence probabilities of small and large cavities increased with increasing diameter at breast height (DBH) for all tree species, the occurrence probabilities of large cavities were <0.08 at 40 cm DBH except for 0.20 in Acer mono and 0.22 in snags. Snags were more likely than live trees to have cavities especially at smaller DBH. The cumulative probabilities that cavities were classified as deep or moderate were positively correlated with DBH and cavity entrance width, and negatively correlated with height of cavity entrance above ground. The variation in occurrence probabilities among cavities of different sizes shows that the classification of cavities by both entrance width and internal dimensions contributes to reliable estimates of cavity availability for different cavity users.     

Effect of citrus pulp silage feeding on concentration of beta‐cryptoxanthin in plasma and milk of dairy cows

Citrus pulp is known to contain a functional molecule of beta‐cryptoxanthin which is one of the carotenoids showing anti‐oxidative capacity. Influences of citrus pulp silage feeding to dairy cows on beta‐cryptoxanthin concentration in plasma, other blood properties and milking performances were investigated. Four Holstein cows were fed total mixed ration (TMR) containing citrus pulp silage 20% dry matter (DM) for 2 weeks with free access to the TMR. Dry mater intake, milk production and milk components 2 weeks later were not altered compared with those of the control group without citrus pulp silage. Activities of aspartate aminotransferase, alanin aminotransferase and gamma‐glutamyltranspeptidase in plasma were not affected by feeding of citrus pulp silage. Concentrations of protein, albumin, sulfhydryl residue, ascorbic acid, thio‐barbituric acid reactive substance and urea nitrogen in plasma were also not altered by citrus pulp silage feeding. Concentration of beta‐cryptoxanthin in plasma was increased approximately 20‐fold compared with the control group (P < 0.05). Content of beta‐cryptxanthin in pooled milk fat fraction was also increased approximately three times compared with that of the control group. Feeding of TMR containing citrus pulp silage 15% DM for 30 days to eight dairy cows also increased plasma beta‐cryptoxanthin concentration 30‐fold compared with that before feeding.