The effect of a new setting agent for wool

Pleated wool fabrics were prepared by the treatment with ethylenediamine (EDA) at 90°C for 30 min. The degree of set, tensile property and dyeing of the treated fabrics have been discussed in relation to the concentration of EDA in the treatment system. No significant decreases in tensile strength and elongation, and great increases of exhaustion of synthetic and natural dyes were observed. Pleat and flat set were successfully attained in a wide range of the concentration of EDA. Excellent dyeability and setability of the fabrics obtained were considered to be associated with the existence of new crosslink, β-N-(2-aminoethyl)alanino-β-aminoalanine and the pendant group, β-N-(2-aminoethyl) aminoalanine produced by the reaction of EDA with dehydroalanine intermediate.     

New Selective Medium for Isolation of Burkholderia glumae from Rice Seeds

A new selective medium for Burkholderia glumae was developed, which has a simpler composition and greater selectivity compared to Tsushima's S-PG medium currently used. This selective medium, designated CCNT, contains 2 g of yeast extract, 1 g of polypepton, 4 g of inositol, 10 mg of cetrimide, 10 mg of chloramphenicol, 1 mg of novobiocin, 100 mg of chlorotharonil and 18 g of agar in 1000 ml of distilled water, and is adjusted to pH 4.8. B. glumae produced a yellowish white colony with a diffusible yellow pigment on CCNT medium, which was distinguishable from other bacterial species when incubated at 41°C for 2 to 4 days. On CCNT medium, B. glumae was detected at a rate similar to that on S-PG medium in rice seeds, while other microorganisms were detected at a much lower rate. Received 16 September 1999/ Accepted in revised form 4 January 2000     

<Emphasis Type="Italic">Tobacco mosaic virus</Emphasis> Is Transmissible from Tomato to Tomato by Pollinating Bumblebees

Tobacco mosaic virus (TMV) was detected by ELISA, electron microscopy and/or bioassay from bumblebee (Bumbus terrestris), pollen clumps, nest materials and bee-visited anthers of flowers from greenhouses in which tomatoes had been pollinated by bees and were severely infected with TMV. Experimental bee-mediated transmission of TMV in greenhouse tomatoes demonstrated that the bumblebees transported TMV from plant to plant and that they spread the virus in greenhouses. This is the first report describing TMV transmission by bumblebees. Received 11 August 1999/ Accepted in revised form 30 September 1999     

GnRHa-induced spawning of wild-caught jack mackerel Trachurus japonicus

The jack mackerel Trachurus japonicus is a key commercially exploited fish species in Japan. The rearing experiment often provides information that is useful for understanding the reproductive characteristics of wild stocks; however, there has been no study on spawning in captive T. japonicus. In the study reported here, we induced spawning in T. japonicus caught in the wild by hook and line. Females with fully vitellogenic oocytes and males during spermiation were selected by gonadal biopsy and injected with gonadotropin-releasing hormone analog (GnRHa) mixed in molten coconut butter. This treatment was performed four times in different groups of four females and five to eight males, and each group was maintained in a 3-m³ concrete tank. We observed the first spawning at 1 or 2 days post-injection and collected between 41,690 and 149,450 eggs. Spawning was recorded on 18 consecutive days in one experiment and for 3 days continuously in the other experiments. In the former, spawning ended when the water temperature reached 23 °C and occurred mainly between 2100 and 2400 hours. These results indicate that GnRHa-induced spawning may be useful for evaluating the reproductive characteristics of T. japonicus and obtaining fertilized eggs to conduct larval experiments.     

Cloning and characterization of 5 MADS-box cDNAs isolated from citrus fruit tissue

We isolated and characterized 5 MADS-box cDNA clones of CitMADS1, CitMADS3, CitMADS5, CitMADS6 and CitMADS8 from fruit tissues of Satsuma mandarin (Citrus unshiu Marc.). Sequence analysis revealed that they have high sequence identities with known MADS-box genes and that their predicted proteins possess the general structural features of the M domain and the K domain. In a phylogenetic tree with 24 known Arabidopsis MADS-box genes, 5 Citrus MADS-box genes were classified into 4 clades of the MADS-box gene with independent gene functions. Their broad expression profiles in the Citrus life cycle suggested that they play roles in flower and fruit development. Most of them, except CitMADS1 and CitMADS3, are expressed in seedlings before the phase transition from vegetative to reproductive growth. CitMADS1 and CitMADS3 are not expressed in vegetative organs and could serve as a molecular marker for reproductive development.     

Retention of Rice dwarf virus by Descendants of Pairs of Viruliferous Vector Insects After Rearing for 6 Years

ABSTRACT Rice dwarf virus (RDV) is characterized by its unusual ability to multiply in both plants and leafhopper vector insects and by its transovarial mode of transmission. Colonies of Nephotettix cincticeps, derived originally from pairs of leafhoppers infected with an ordinary strain of RDV, were maintained for 6 years in the laboratory and were found, at the end of this time, still to harbor RDV. Moreover, the isolate of RDV, designated RDV-I, obtained from these colonies retained the ability to infect rice plants. When we raised leafhoppers separately from eggs that had been placed individually on pieces of water-soaked filter paper and reared them in the presence of healthy rice seedlings, we found that all of these leafhoppers harbored RDV. This observation suggested that RDV-I had been maintained in the leafhoppers by transovarial transmission. Two further observations, namely, the low rate of acquisition of RDV by virus-free insect nymphs on symptomless plants on which viruliferous insects had been reared, and the fact that only 2 to 5% of plants had symptoms when rice seedlings were inoculated via RDV-I-viruliferous insects, confirmed that the maintenance of RDV-I by any other mode of transmission through plants and insects was unlikely. This efficient and long-term maintenance of RDV in a population of viruliferous insects might explain the prolonged duration of rice dwarf disease in the field, once there has been a serious outbreak.     

Molecular characterisation of equine group A rotavirus, Nasuno, isolated in Tochigi Prefecture, Japan

In this study, equine group A rotavirus (RV-A), Nasuno, isolated from foal diarrhoea in Tochigi Prefecture, Japan was characterised genetically by sequence analysis of the genome segments encoding VP4 and VP7. The nucleotide and deduced amino acid sequences revealed high homology with P[12] RV-As (94.0-99.3% and 94.9-99.4%) and G3 RV-As (86.9-99.5% and 91.1-99.4%). Nasuno was also classified into P[12] and G3 in the phylogenetic analysis of the nucleotide sequences of the genome segments encoding VP4 and VP7.     

Impact of paralarvae and juveniles feeding environment on the neon flying squid (Ommastrephes bartramii) winter–spring cohort stock

In this study, we found that there were significant positive correlations between the catch per unit effort (CPUE, a squid abundance index) for the neon flying squid (Ommastrephes bartramii) winter–spring cohort and the satellite‐derived chlorophyll a concentrations in their spawning grounds located at 140–160°E where 21°C < sea surface temperature < 25°C from February to May. The spawning grounds of the winter–spring cohort are located in a quiet stream region, and a particle tracking experiment, based on the velocity field obtained from an ocean data assimilation system, showed that paralarvae and juveniles aged <90 days remained in their spawning grounds and the chlorophyll a concentration in their habitat had a significant positive correlation with the CPUE. A backward particle tracking experiment also showed that the chlorophyll a concentration in the spawning grounds had a significant positive correlation with the autumn–winter mixed layer depth. Based on these results, we hypothesize that the CPUE interannual variability is caused by variations in the feeding environment of the paralarvae and juveniles, which may be linked to autumn–winter mixed layer depth variations.     

Relationship between indocyanine green clearance test and feed intake and impaired hepatic function in dairy cows

The purposes of this study were 1) to examine changes in the indocyanine green (ICG) clearance by feeding and 4-day fasting in dry cows, and (2) to investigate the relationship between ICG clearance and blood chemistry profile in postpartum cows. In 3 dry cows, post-feeding ICG half-life (T(1/2)) was shorter than the pre-feeding value, and post-fasting T(1/2) was longer than pre-feeding and post-feeding values. In 16 lactating cows, T(1/2) value at 2 weeks postpartum showed positive correlations with AST, T-Bil and γ-GTP. These results suggested that ICG clearance correlated with T-Bil and liver enzymes can be sensitive and accurate diagnostic marker for impaired liver function in dairy cows. In addition, ICG clearance is greatly affected by feeding and fasting.     

Circadian rhythms and individual variability of self-feeding activity in groups of rainbow trout Oncorhynchus mykiss (Walbaum)

An experiment was conducted to examine whether circadian self‐feeding rhythms exist in groups of rainbow trout Oncorhynchus mykiss (Walbaum) and to investigate individual variability of self‐ feeding and its influence on growth. Ten trout of 144.9 ± 12.0 g (mean ± SD) were transferred to each of eight 290‐L tanks and given free access to feed via a self‐feeder. Fish in four of the eight groups were individually tagged, and the individual activating the trigger was identified using video observations. The self‐feeding activity of each group was recorded under a light:dark cycle of 16.5:7.5 h and under continuous light (LL) conditions. Although diel self‐feeding rhythms in the groups of trout were, in general, diurnal, night‐feeding activity was observed in the initial LD phase, but there was a progressive reduction and eventual cessation in most groups. Endogenous circadian self‐feeding rhythms were detected in the groups of trout under LL conditions. The trout formed dominance hierarchies of self‐feeding activity, with one or two individuals accounting for the majority of trigger actuations. However, the dominants did not occupy the area surrounding the trigger. Growth rates did not differ significantly between the dominants and the subordinates within the groups.