Effect of ovarian hormones on maturation of dendritic cells from peripheral blood monocytes in dogs

Previously, we reported that ovarian hormones affect the immune response against E. coli isolated from the dogs affected with pyometra. In order to investigate mechanisms underlying the immune modulation, we examined the effects of ovarian hormones on the generation of dendritic cells (DCs), the most potent antigen presenting cell. DCs were differentiated from peripheral blood monocytes (PBMOs) using a cytokine cocktail. Both estrogen receptor and progesterone receptors were expressed by the PBMOs and immature DCs. When various ovarian hormones were added to the culture for the DC differentiation, progesterone significantly decreased the expression of DC maturation markers, such as CD1a, CD80 and CD86, on mature DCs. Conversely, the addition of estrogen to the cultures increased the expression of CD86, but not other maturation makers. Furthermore, DCs differentiated in the presence of progesterone did not stimulate allogeneic mononuclear cells in PB. Taken together, these results indicate that progesterone diminishes the maturation of DCs, leading to decreased immune responses against invading pathogens.     

Mitigation of nitrous oxide (N2O) emission from swine wastewater treatment in an aerobic bioreactor packed with carbon fibers

Mitigation of nitrous oxide (N₂O) emission from swine wastewater treatment was demonstrated in an aerobic bioreactor packed with carbon fibers (CF reactor). The CF reactor had a demonstrated advantage in mitigating N₂O emission and avoiding NOx (NO₃ + NO₂) accumulation. The N₂O emission factor was 0.0003 g N₂O‐N/gTN‐load in the CF bioreactor compared to 0.03 gN₂O‐N/gTN‐load in an activated sludge reactor (AS reactor). N₂O and CH₄ emissions from the CF reactor were 42 g‐CO₂ eq/m³/day, while those from the AS reactor were 725 g‐CO₂ eq/m³/day. The dissolved inorganic nitrogen (DIN) in the CF reactor removed an average of 156 mg/L of the NH₄‐N, and accumulated an average of 14 mg/L of the NO₃‐N. In contrast, the DIN in the AS reactor removed an average 144 mg/L of the NH₄‐N and accumulated an average 183 mg/L of the NO₃‐N. NO₂‐N was almost undetectable in both reactors.     

Photoinhibition, carotenoid composition and the co-regulation of photochemical and non-photochemical quenching in neotropical savanna trees

Plants in the neotropical savannas of central Brazil are exposed to high irradiances, high air temperatures and low relative humidities. These conditions impose a selection pressure on plants for strong stomatal regulation of transpiration to maintain water balance. Diurnal adjustments of non-photochemical energy dissipation in photosystem II (PSII) provide a dynamic mechanism to reduce the risk of photoinhibitory damage during the middle of the day when irradiances and leaf temperatures are high and partial closure of the stomata results in considerable reductions in internal CO(2) concentration. At the end of the dry season, we measured diurnal changes in gas exchange, chlorophyll fluorescence parameters and carotenoid composition in two savanna tree species differing in photosynthetic capacity and in the duration and extent of the midday depression of photosynthesis. Non-photochemical quenching and its quantum yield were tightly correlated with zeaxanthin concentrations on a total chlorophyll basis, indicating that the reversible de-epoxidation of violaxanthin to antheraxanthin and zeaxanthin within the xanthophyll cycle plays a key role in the regulation of thermal energy dissipation. In both cases, a single linear relationship fitted both species. Although efficient regulation of photochemical and non-photochemical quenching and adjustments in the partitioning of electron flow between assimilative and non-assimilative processes were operating, these trees could not fully cope with the rapid increase in irradiance after sunrise, suggesting high vulnerability to photoinhibitory damage in the morning. However, both species were able to recover quickly. The effects of photoinhibitory quenching were largely reversed by midday, and zeaxanthin rapidly converted back to violaxanthin as irradiance decreased in late afternoon, resulting in the maximal quantum yield of PSII of around 0.8 just before sunrise.     

PCR-SSCP analysis of <Emphasis Type="Italic">Fusarium</Emphasis> diversity in asparagus decline in Japan

The diversity of Fusarium populations in asparagus (Asparagus officinalis L.) decline fields in Japan was estimated by PCR-SSCP (single-stranded conformational polymorphism) analysis of the ITS2 regions of the nuclear rRNA genes. This method was used to rapidly and objectively identify pathogens associated with roots of plants showing symptoms of asparagus decline collected from fields in five regions across Japan. Over 651 fusarial isolates were obtained, and were easily differentiated into three principal species. Fusarium oxysporum f. sp. asparagi was most frequently isolated from the domestic five regions (68%), whereas Fusarium proliferatum (28.6%) was less frequent. Fusarium solani was found much rarely (2.5%). The frequency of isolation of Fusarium proliferatum increased gradually from the north to the south of Japan, though considerable differences were found between fields in each region, as well as regional differences among the Fusarium populations. Most of the fusarial isolates were highly pathogenic in vitro. These results reveal that Fusarium oxysporum f. sp. asparagi and Fusarium proliferatum are important biotic factors which lead to asparagus decline in Japan.     

Performance of Bangladesh indigenous rice in a weed infested field and separation of allelopathy from resource competition

This study aimed to identify the potential allelopathic indigenous rice (Oryza sativa L. ssp. indica) varieties from Bangladesh using a performance study in a weed‐infested field and to assess the extent of allelopathic interference relative to resource competition in a glasshouse experiment. Six varieties – namely, “Boterswar,” “Goria,” “Biron” and “Kartiksail” as the most allelopathic, “Hashikolmi” as weakly allelopathic and “Holoi” as nonallelopathic – were raised following a nonweed control method. The infestation levels of weed species were calculated using Simpson's Diversity Index (SDI), which ranged from 0.2 to 0.56. However, a significant correlation coefficient (0.87, P < 0.001) was obtained from these field data compared with the root inhibition percentage from the laboratory bioassay, and the “Boterswar” variety was the most allelopathic. The interactions between the allelopathic variety “Boterswar,” weakly allelopathic variety “Hashikolmi” and Echinochloa oryzicola via a target (rice)‐adjacent (E. oryzicola) cogrowth culture were determined in a hydroponic arrangement. The relative competitive intensity (RCI) and the relative neighbor effect (RNE) values showed that the crop–weed interaction was facilitation for “Boterswar” and competition for “Hashikolmi” and E. oryzicola in rice/E. oryzicola cogrowth cultures. The allelopathic effects of “Boterswar” were much higher than the resource competition in rice/E. oryzicola cogrowth cultures. The converse was observed for “Hashikolmi.” Moreover, the mineral content of E. oryzicola was severely affected by “Boterswar”/E. oryzicola cogrowth cultures’ exudate solution. Therefore, the allelopathic potential of “Boterswar” variety might be useful for developing the weed‐suppressing capacity of rice, which will likely have a significant influence on paddy weed control.     

Overcoming the self-incompatibility of Raphanus sativus by application of plant hormones,amino acids and vitamines,and by temperature treatment of pollen

Summary Overcoming self-incompatibility by application of three kinds of plant hormones, sucrose, 3 kinds of amino acids and 2 kinds of vitamines was tested in cvs. Honbashi-taibyo Minowase (H-Mino) and Minowase (Mino) of Raphanus sativus. Effects differed between the cultivars. In H-Mino, BA (100 mg/l) and glutamic acid, folic acid and nicotinic acid (500 mg/l) resulted in higher fruit set and higher number of seeds per pollinated flower. In Mino, BA and NAA (100 mg/l) and glutamic acid and glycine (500 mg/l) induced a high number of seeds per pollinated flower. These chemicals, however, induced parthenocarpic fruit set, especially GA3. From the observation of pollen on stigmas washed with glutamic acid, it appeared that the pollen-tube penetrated into a papilla cell after 1 hour and openings of papillae and detached pollen grains and tubes were found after 2 hours as the result of successful pollentube penetration of papillae. Pollen was heated at 50°C for 30, 45 or 60 minutes, at 60°C for 15, 30 or 45 minutes and at 70°C for 10, 20 or 30 minutes prior to self-pollination. In H-Mino, 60 and 70°C were effective, and expecially 60°C for 15 or 30 minutes resulted a higher percentage fruit set and more seeds per fruit. In Mino, although 50–70°C were effective, the mean number of seeds per pollinated flower was lower than in H-Mino.     

Development of a screening method for genetically modified soybean by plasmid-based quantitative competitive polymerase chain reaction

A novel type of quantitative competitive polymerase chain reaction (QC-PCR) system for the detection and quantification of the Roundup Ready soybean (RRS) was developed. This system was designed based on the advantage of a fully validated real-time PCR method used for the quantification of RRS in Japan. A plasmid was constructed as a competitor plasmid for the detection and quantification of genetically modified soy, RRS. The plasmid contained the construct-specific sequence of RRS and the taxon-specific sequence of lectin1 (Le1), and both had 21 bp oligonucleotide insertion in the sequences. The plasmid DNA was used as a reference molecule instead of ground seeds, which enabled us to precisely and stably adjust the copy number of targets. The present study demonstrated that the novel plasmid-based QC-PCR method could be a simple and feasible alternative to the real-time PCR method used for the quantification of genetically modified organism contents.     

Improvement of antifungal activity of 10-undecyn-1-ol by inclusion complexation with cyclodextrin derivatives

The inclusion complexation behavior between 10-undecyn-1-ol and cyclodextrin (CD) derivatives, namely, randomly methylated beta-CD (RM-beta-CD) and hydroxypropyl-beta-CD (HP-beta-CD), was studied in terms of solubility improvement, apparent stability constant, and the inclusion ratios of the resultant inclusion complexes. The aqueous solubility of 10-undecyn-1-ol was greatly improved through complexation with the CD derivatives. RM-beta-CD is comparatively more efficient in solubilizing 10-undecyn-1-ol with an apparent stability constant outstripping that of HP-beta-CD by about an order of magnitude. Comparative in vitro evaluations of the growth inhibition effects of inclusion complex solutions toward Rosellinia necatrix, a phytopathogenic fungus, were performed. In comparison with the positive control, appreciable improvements of the antifungal activity of 10-undecyn-1-ol through the addition of CD derivatives were observed visually. The improvement was evaluated in terms of area covered by the mycelia of Rosellinia necatrix and their growth rate. RM-beta-CD was proven to be more effective compared to HP-beta-CD with regard to the reduction of both fungal mycelium-covered area and growth rate constant, presumably owing to greater solubility enhancement by RM-beta-CD and thus the bioavailability of 10-undecyn-1-ol. Inclusion complexation of 10-undecyn-1-ol with CD derivatives suggests a potential means for production of an environmentally friendly 10-undecyn-1-ol-based fungicide to counteract R. necatrix.     

Estimation of kelp forest, <Emphasis Type="Italic">Laminaria</Emphasis> spp., distributions in coastal waters of the Shiretoko Peninsula,Hokkaido, Japan,using echosounder and geostatistical analysis

Sustainable management of the kelp forests of the Shiretoko Peninsula, a World Natural Heritage site, is necessary due to kelp’s ecological and economic importance. The objectives of this study were to estimate the area of kelp forests and to clarify their spatial characteristics in coastal waters of the Shiretoko Peninsula. Data on the presence/absence and thickness of kelp forests were collected via acoustic observation on transects over about 80 km using an echosounder at 200 kHz. Acoustic data were geostatistically interpolated, and the areas covered by kelp forests were estimated. Differences in kelp distribution between the eastern and western sides of the peninsula were compared. The total area of kelp forest was 3.88 km² (eastern area: 3.49 km²; western area: 0.39 km²). The range of thickness of the kelp forests was 34–91 cm. Many kelp forests in the eastern area were thick (>78 cm) and distributed continuously, while kelp forests in the western area were sparsely distributed.     

Beneficial effects on meat quality of yellowtail Seriola quinqueradiata induced by diets containing red pepper

The meat quality of farmed yellowtail Seriola quinqueradiata fed on extruded pellets (EP) containing 0.5% (v/v) red pepper (experimental group) was compared with yellowtail of the same age fed on EP (control group). In 1-year-old yellowtail, the crude lipid content of the dorsal muscle of the experimental group tended to be lower than that of the control group. In contrast, there was no difference in the lipid content of the dorsal muscle between the control group and the experimental group in 2-year-old yellowtail. The muscle texture of the experimental group was significantly firmer than that of the control group, with the effect of red pepper unrelated to fish age and lipid content. Color change of red muscle of the experimental group was significantly lower than that of the control group, and the content of thiobarbituric acid-reactive substances in the red muscle was significantly lower in the experimental group than in the control group. These results are the first to demonstrate that the inclusion of red pepper in the diet is able to reduce the loss of muscle texture firmness and to slow down color change in red muscle of yellowtail.