Evaluation of novel sulfonylurea derivatives with a fused heterocyclic moiety as paddy herbicides that control sulfonylurea‐resistant weeds

Herbicidal activity and acetolactate synthase (ALS) inhibition of sulfonylurea derivatives with a fused heterocyclic moiety bonded to a sulfonyl group were investigated. Some compounds that had an imidazo[1,2‐b]pyridazine moiety substituted at the 2‐position by chlorine or methyl controlled sulfonylurea‐resistant (SU‐R) weeds and showed inhibitory activity to ALS prepared from SU‐R Schoenoplectus juncoides shoot. There was a correlation between in vitro and whole‐plant herbicidal activity of the compounds mentioned above against SU‐R Schoenoplectus juncoides. Among them 1‐(2‐chloro‐6‐propylimidazo[1,2‐b]pyridazin‐3‐ylsulfonyl)‐3‐(4,6‐dimethoxypyrimidin‐2‐yl)urea, propyrisulfuron, was selected for further evaluation. Propyrisulfuron effectively controlled paddy weeds at doses of 70 and 140 g a.i. ha^?1 with good rice selectivity in a field trial.     

Extractable sugar contents of trunks from fruiting and nonfruiting oil palms of different ages

Oil palm trunks (OPTs) are a potential source of sugars for bioethanol production, and so we determined the glucose, fructose, and sucrose contents of hot water extracts from OPTs. Samples of OPTs were obtained from different regions of the trunk, from trunks of palms of different ages (31-, 19-, and 15-year-old), and from fruiting and nonfruiting palms. The extractable sugar contents of the whole OPT and the upper and lower regions of each OPT were calculated. Our results indicated that the upper parts of OPTs should be used for bioethanol production because they yield higher concentrations of sugars than the lower parts do. To produce a highly concentrated glucose solution for bioethanol production, OPTs should be harvested as soon as production of palm oil has been completed and when new male flowers have appeared. If these suggestions are followed, then the estimated ethanol concentration after fermentation is 3.2% and the estimated ethanol production per harvested area is 3.5 kl/ha.     

Oogenesis in the common Japanese conger Conger myriaster

ABSTRACT:    We investigated the process and characteristics of oogenesis in the common Japanese conger Conger myriaster . Young fish caught in November 1996 were reared for use in this experiment. Fish were sampled monthly from December 1997 to August 1998. Some were injected with human chorionic gonadotropin to stimulate ovarian maturation from May to August 1998. Oocytes from the chromatin nucleolus stage to the secondary yolk globule stage were obtained from non-hormone-treated fish; those of more advanced stages were obtained from hormone-treated ones. We divided oocyte development into eight stages from the chromatin nucleolus stage to the maturation stage. The yolk vesicle stage was not separated because yolk vesicles began to appear just after appearance of yolk globules. Oocyte, oil droplet, yolk globule and nucleus diameters all increased concomitant with oocyte development. Oil droplet and yolk globule diameters increased remarkably at the maturation stage. However, zona radiata thickness peaked at the secondary yolk globule stage, decreasing gradually thereafter. Increased gonadosomatic index was related to oocyte development as found in European and Japanese eels receiving hormone treatment to mature. The present study is the first report describing oogenesis characteristics in congrid eels. It indicates that oogenesis is almost identical to that of other anguillid eels.     

Dietary vitamin A requirements of juvenile Japanese flounder Paralichthys olivaceus

A 70‐day feeding experiment was conducted to assess the dietary vitamin A (VA) requirements of juvenile Japanese flounder (Paralichthys olivaceus). Six semi‐purified diets with VA supplementations of 0, 5000, 10 000, 15 000, 20 000 and 25 000 IU kg^?1 were fed twice a day to triplicate groups of 20 juveniles per tank with an initial weight of 1.59 ± 0.01 g (mean ± SE). Weight gain (WG) and specific growth rate (SGR) increased as dietary VA increased up to 10 000 IU kg^?1. Significantly lower WG and SGR were observed for the 0 IU kg^?1 treatment than for treatments of 5000, 10 000 and 15 000 IU kg^?1. Highest WG and SGR were observed in fish fed 10 000 IU kg^?1; slightly lower values were recorded in fish fed 15 000, 20 000 or 25 000 IU kg¹. No significant difference was observed in survival rate among treatments. Whole body total lipid was significantly higher in fish fed 0 and 5000 IU kg^?1 than for other levels. Reduced growth and small livers were observed as signs of VA deficiency in fish fed 0 IU kg^?1. Slightly reduced growth and pale fragile livers were observed as effects of VA excess in fish fed 25 000 IU kg^?1. Total retinol contents in liver and eyes increased with increasing levels of dietary VA. No retinol was detected in livers, and significantly lower total retinol content was observed in eyes, of fish fed 0 IU kg^?1. WG analysed by the broken line method indicated that an optimum dietary VA requirement of 9000 IU kg^?1.     

Non‐invasive sampling technique for DNA extraction from captive Japanese Crested Ibis on Sado Island

The Japanese Crested Ibis Nipponia nippon is a critically threatened bird. The post‐hatch eggs of the current captive population of this species on Sado Island have been stored at room temperature for the long‐term. In this study, we investigated the suitability of the vascularized chorioallantois membrane from the eggs as a non‐invasive DNA source. Using microsatellite loci developed for the Japanese Crested Ibis, we performed three experiments for comparison of genotypes obtained among DNA. First, DNA from five different sites of the identical membrane showed the same genotypes at either of two loci examined. Second, DNA from the membrane of each full‐sibling birds and blood of their parents showed the genotypes that were consistent with Mendelian parent–offspring relationships at any of eight loci examined. Third, DNA from the membrane and blood of the same bird showed the matched genotypes at any of eight loci examined. These results indicate that the vascularized chorioallantois membrane from post‐hatch eggs stored at room temperature for the long‐ term can be used as a reliable DNA source of offspring that had hatched from the egg. This study will promote a molecular genetics study on genetic diversity of the current captive Japanese Crested Ibis population on Sado Island.     

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.     

Radiotherapy-induced tumor lysis syndrome in a dog with thymoma

A 13-year-old, female, mixed-breed dog with a huge cranial mediastinal mass underwent radiotherapy (RT). On the following day, the dog presented with lethargy and anorexia. Hematological examination revealed elevated levels of blood urea nitrogen, creatinine, inorganic phosphorus, potassium, lactate dehydrogenase, creatine phosphokinase and aspartate aminotransferase, decreased calcium level, and metabolic acidosis. Urine output markedly decreased. The patient recovered with fluid therapy and diuretic therapy; however, died suddenly from an unknown cause 11 days after RT completion. Histopathological examination after necropsy showed thymoma in the cranial mediastinum and extensive tubular necrosis of both kidneys which may be due to RT-induced tumor lysis syndrome (TLS). This report suggests that the risk of TLS should be evaluated in dogs with thymoma who undergo RT.     

Calming effect of orally administered γ‐aminobutyric acid in Shih Tzu dogs

The calming effects of γ‐aminobutyric acid (GABA) by oral administration were investigated in four adult Shih Tzu dogs. Three dosage levels (1, 2 and 4 mg/kg body weight) and non‐administration were tested by an increase and decrease method. Changes in activity (for 1.5 h) and urinary cortisol levels (pre‐administration, 3 and 7 h later) of dogs were monitored after administration. Without reference to dosage level, the mean times spent standing (P = 0.06), sitting (P < 0.05) and walking (P < 0.05) tended to decrease compared to non‐administration. A significant depression in the urinary cortisol level was observed at 7 h after administration (P < 0.05). These results indicate that orally administrated GABA exerts calming effects on dogs as well as humans.     

Comparison of carbon skeletal structures in black humic acids from different soil origins

Andosols are characterized by an abundance of black humic acids (HAs) belonging to Type A with a high content of aromatic carbon (C) in particular condensed aromatic C. Black HAs are also observed in other soils, such as Chernozems and the subsoil of paddy field, and extracted after washing with an acid or using chelating agent such as sodium pyrophosphate (Na₄P₂O₇). However, contribution of condensed aromatic structures to those soil HAs are unknown. To obtain the information about C skeletal structures of black HAs in soils other than Andosols, HAs were obtained from 2 Chinese Chernozem samples, 2 subsoil samples from Japanese paddy fields (Fulvisols), and a Rendzina-like soil (Cambisols) as well as an Andosol sample (reference) by successive extraction with 0.1 M NaOH (HAs₁) and 0.1 M Na₄P₂O₇ (HAs₂), and ¹³C nuclear magnetic resonance and X-ray diffraction 11-band profile analyses were applied. In the black HAs₂ from the non-Andosol samples, the proportion of C present as aromatic C, size of C layer planes, and relative C layer plane content ranged from 52 to 59%, 0.48 to 1.92 nm (mean size, 0.76–0.91 nm), and 58 to 100 AU (arbitrary unit) mg^?1, respectively, with a positive correlation between total C layer plane content and the degree of humification. Those ranges were similar to the distribution ranges of Andosols HAs₁ reported by our previous study.