Synthesis and insecticidal activity of novel 1,3,4-oxadiazolin-5-one and pyrazolin-5-one derivatives

A series of novel 2-(2,4,6-trisubstituted phenyl)-1,3,4-oxadiazolin-5-one derivatives and 3-(2,4,6-trichlorophenyl)pyrazolin-5-one derivatives were synthesized and evaluated for insecticidal activity. It was found that a moderately bulky alkyl group, such as a tert-butyl group, on the heterocyclic ring, and a trifluoromethyl group on the benzene ring were optimal substituents on the molecule. The oxygen atom in the oxadiazoline ring was essential for insecticidal activity. Of the compounds assayed, 4-tert-butyl-2-(2,6-dichloro-4-trifluoromethylphenyl)-1,3,4-oxadiazolin-5-one gave the highest activity against Nephtotettix cincticeps, with an LC₅₀ value of 0.51 mg litre⁻¹. © 1999 Society of Chemical Industry     

Temperature and fatigue effect on the maximum swimming speed of jack mackerel Trachurus japonicus

Swimming performance of jack mackerel Trachurus japonicus (18.2 ± 0.8 cm fork length (FL), n = 185) was examined in a flume tank by measuring the stride length at low and high tail beat frequencies with electromyogram monitoring and a muscle twitch experiment. Stride length was analyzed by monitoring the tail beat frequency according to the swimming speed at different temperatures of 10, 15 and 22 °C. In the electromyographic observations, the initiation of ordinary muscle activity occurred between 71.4 and 99.6 cm/s, that is 3.7 to 5.3 FL/s, when the tail beat frequency was over 6 Hz. The swimming speeds increased rectilinearly with the tail beat frequency at each water temperature both for the low and high tail beat frequency. Lower stride length was observed at the lowest temperature (10 °C) tested. The forced swimming exercise significantly affected the muscle contraction time to become longer than the control fish, which indicated a reduction of the maximum swimming speed performance.     

Assessment of DNA markers for seed contamination testing and selection of disease resistance in cabbage

Cabbage (Brassica oleracea L. var. capitata) is an important vegetable worldwide. Most Japanese commercial cultivars of cabbage use an F₁ hybrid seed production system. The purity of F₁ hybrid seeds is important and the assessment of purity based on DNA markers can be highly accurate. In addition, selection of agronomically important traits such as disease resistance based on DNA markers is useful for breeding of cabbage. The aim of this study is to demonstrate the effectiveness of DNA marker-assisted selection in cabbage. In this study we distinguished the parental S haplotypes in 35 F₁ hybrid cultivars by combining several linked DNA markers. Thirty-one highly polymorphic simple sequence repeats (SSR) markers were screened from 175 reported SSR markers, which are useful for assessment of the purity of F₁ hybrid seeds. We examined the relationship between the DNA marker based genotype and the phenotype by an inoculation test of clubroot disease. A co-dominant PCR–RFLP marker was developed for selection of Fusarium yellows resistance and the genotypes using this marker were consistent with inoculation test in all tested samples.     

Measurement of urinary mesotocin in large-billed crows by enzyme-linked immunosorbent assay

Mesotocin (MT) is an avian homologue of oxytocin (OT). Behavioral pharmacological studies in birds have suggested the involvement of MT in socially affiliative behavior. However, investigations of peripheral MT levels associated with social behavior are lacking because non-invasive methods to measure surrogate plasma MT have yet to be established. This study aimed to measure urinary MT in crows using a commercially available OT enzyme-linked immunosorbent assay kit. Urine samples were collected after intravenous injection of MT and centrifuged to separate urine and fecal components. We found that urinary MT was significantly elevated 15–30 min after MT injection. These results validate our method for the use of urine samples for the measurement of peripheral MT levels in crows.     

Administration of tetrodotoxin protects artificially raised juvenile tiger puffer <Emphasis Type="Italic">Takifugu rubripes</Emphasis> from predators

We examined the effects of tetrodotoxin (TTX) administration on artificially raised tiger puffer Takifugu rubripes juvenile survival after release into a mesocosm with predators to clarify the ecological significance of TTX. Pellets containing three different concentrations of TTX [0 as the control, 7 and 14 mouse units (MU)/g diet] were fed to non-toxic artificially raised T. rubripes juveniles for 10 days. TTX accumulation in the various tissues of fish was detected except for in the control diet group. TTX administration did not affect survival or growth of the fish. One hundred fish from each diet group were released together after TTX administration into a salt pond mesocosm (2650 m²) with predators (Lateolabrax sp.) for 5 days. Survival after release was significantly higher in both the fish fed with the 7 MU TTX/g diet (62%) and the 14 MU TTX/g diet (74%) than in the control fish (32%).     

A trial to detect optimal pin-pricking timing in evaluating the ability to form traumatic resin canals of <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> for selecting resistant trees to <Emphasis Type="Italic">Semanotus japonicus</Emphasis> (Coleoptera: Cerambycidae)

A trial to detect optimal pin-pricking timing in evaluating the ability to form traumatic resin canals (TRCs) of Cryptomeria japonica was examined to select resistant trees to Semanotus japonicus using 14 clones in 2001 and 2002. Resistance to S. japonicus and the ability to form TRCs in the phloem was evaluated by inoculating newly hatched larvae in the bark and by a pin prick, which was conducted every 10 days (four times) on the trunk around the larval phloem-feeding period, respectively. The larval survivorship varied greatly among clones for both years. The mean appearance of newly formed TRCs was generally higher in late treatment for both years, and the tangential width of them was also higher in 2001, whereas those of pre-formed TRCs were not higher for either year. The larval survivorship did not show significant correlations with the appearance and the width of pre-formed TRCs on all treatments. However, it showed significant negative correlations with the appearance of newly formed TRCs on the second and third treatments on the 2-year-old layer, although this was not significant with the width of them. This suggests that resistant clones might have the mechanism of rapidly forming TRCs when just at the stage of newly hatched larval entering the phloem. Thus, although the relationship between the appearance and the width of newly formed TRCs is not clear, pin-pricking treatment when the newly hatched larvae just enter the bark may be one of optimal times for the evaluation of the resistance of C. japonica to S. japonicus. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Extractives ofJuniperus chinensis L. I: Isolation of podophyllotoxin and yatein from the leaves ofJ. chinensis

Two compounds, yatein and podophyllotoxin, were isolated from the chloroform-soluble fraction in the methanolic extractives of byakushin (Juniperus chinensis L.) leaves for the first time.This report was presented at the 47th annual meeting of the Japan Wood Research Society, Kochi, 1997     

Inflexibility of vertebral number in chum salmon <Emphasis Type="Italic">Oncorhynchus keta</Emphasis>

Chum salmon Oncorhynchus keta eggs from the Chitose and Shiriuchi rivers in Hokkaido, northern Japan, were incubated under identical conditions with the aim of comparing vertebral number (V _N) to that reported archived data from the 1950s. The comparison revealed that mean V _N of salmon from the Shiriuchi River has remained unchanged for 50 years and is higher than that from the Chitose River. The V _N in the Chitose River salmon was found to be significantly higher than that recorded in the archival data. The variation in the mean V _N of chum salmon fry collected during different seasons and years in the Chitose River falls within a range that has remained constant, suggesting that the difference between the values obtained in our study and the archival data may be due to differences in the timing of egg collection. These results indicate that the mean V _N of chum salmon has been stable for a long period. Incubation experiments under identical conditions are a useful tool for examining changes in genetic structure and detecting the essential properties of populations.     

Prevalence of intestinal parasites in private-household cats in Japan

The present study is the first national investigation of intestinal parasites in private-household cats in Japan. A total of 942 faecal samples were collected from private-household cats. Giardia species was assessed using an enzyme-linked immunosorbent assay kit and other intestinal parasites were identified microscopically. The overall prevalence of intestinal parasites was 10.1%; two protozoan parasites (Giardia species and Cystoisospora species) and five helminths (Toxocara cati, Toxascaris leonina, Ancylostoma tubaeforme, Taenia species and Spirometra erinacei) were detected. The total prevalence of intestinal parasite infection was significantly higher in cats aged ≤ 6 months old than in cats older than 6 months because of a significantly higher prevalence of Cystoisospora species and T cati. The total infection prevalence was higher among outdoor cats as a result of the significantly higher prevalence of T cati and S erinacei. Sex and faecal condition were not related to intestinal parasite infections. Regional differences were observed in Cystoisospora species and A tubaeforme.     

Effect of aeration in reducing phytotoxicity in anaerobic digestion liquor of swine manure

Numerous reports have accumulated concerning the quality of solid compost. In contrast, there are few for the residue of anaerobic digestion. In this study, the fertilizer value of anaerobic digestion liquor (ADL) was evaluated, and the effect of aeration on the reduction of the phytotoxicity was examined by a germination assay. Low or high aeration (100 or 400 mL/min) was added to 3 L of ADL obtained from a mixture of pig manure and garbage by using 5‐L jar fermenters under a controlled temperature of 30°C. During the 14‐day aeration period, a high aeration rate improved the germination index (GI) score from 5.7% to nearly 80%, while a low aeration rate did not. Although organic matter decomposition, determined as chemical oxygen demand, did not differ with aeration intensity, remarkable differences were observed in the time course of changes in pH, electric conductivity and ammonium‐nitrogen (NH₄‐N) and total nitrogen (T‐N) content. Among these parameters, the NH₄‐N concentration correlated highly with the GI score (r = 0.986). The primary phytotoxic element in ADL was considered to be NH₄‐N, and the stripping of ammonia (NH₃) by high aeration resulted in the improvement of the GI score. Although the ratio of major nutrients N : P₂O₅ : K₂O (1:0.41:0.94) in ADL was at nearly same level as conventional liquid fertilizer, special attention should be paid to the high concentration of NH₃ when drawing up a fertilization plan.