Inhibition of chitin biosynthesis by buprofezin analogs in relation to their activity controlling Nilaparvata lugens Stål

Buprofezin (Applaud, 2-tert-butylimino-3-isopropyl-5-phenyl-3,4,5,6-tetrahydro-2H-1,3,5-thiadiazin-4-one) strongly inhibited the [³H]chitin synthesis from N-acetyl-d-[1-³H]glucosamine in the brown rice planthopper, Nilaparvata lugens Stål. No inhibition was observed for [³H]-labeled protein biosynthesis from [5-³H]glucose or l-[3,5-³H]tyrosine but [³H]-labeled nucleic acid synthesis from [5-³H]glucose was weakly reduced by buprofezin. The lethal activity of buprofezin analogs related well to their inhibitory potency against chitin biosynthesis in N. lugens nymphs.     

A new pyrethroid-type ester with strong knockdown activity

Thirteen pyrethroid-type esters of substituted 1(or 3)-hydroxymethylimidazolidine-2, 4-dione were synthesised and their knockdown activities against houseflies, mosquitoes and cockroaches were examined. Knockdown activities of 2,4-dioxo-1-prop-2-ynylimidazolidin-3-ylmethyl esters in oil solutions were higher than those of known knockdown pyrethroids; three of the compounds also possessed strong knockdown and flushing-out activities against cockroaches.     

Glucose metabolism in detached leaves of tomato plants grown with ammonium and nitrate as nitrogen sources

The metabolism of exogenous glucose-¹⁴C in the light and the dark was studied in the detached leaves of tomato plants grown with ammonium nitrogen and nitrate nitrogen. In the light, ¹⁴CO₂, release and incorporation of glucose into insoluble materials were hardly affected at all by the nitrogen sources. Among the soluble labelled amino acids, serine had the greatest amount of label in the ammonium-plants while aspartate had the greatest amount in the nitrate-plants. This aspartate was synthesized from C₃-compounds by carboxylation. During dark-light transition, the change in the composition of soluble amino acids was more rapid in the ammonium-plants than in the nitrate-plants. In the dark, ¹⁴CO₂-release, which was ten times as much as in the light, was larger in the ammonium-plants than in the nitrate-plants; but the synthesis of high molecular compounds from glucose in the ammonium-plants was about half that in the nitrate-plants. So, it is considered that respiration operates sufficiently in the ammonium-plants. The effects of DCMU and a 100% O₂ atmosphere on glucose metabolism in both groups of plants were studied and the respiration of leaves in the light was discussed.     

Kazakhstani native cattle reveal highly divergent mtDNA from Bos taurus and Bos indicus lineages with an absence of Bos indicus Y chromosome

Kazakhstan is the largest landlocked country and contains two important propagation routes for livestock from the Fertile Crescent to Asia. Therefore, genetic information about Kazakhstani cattle can be important for understanding the propagation history and the genetic admixture in Central Asian cattle. In the present study, we analyzed the complete mtDNA D‐loop sequence and SRY gene polymorphism in 122 Kazakhstani native cattle. The D‐loop sequences revealed 79 mitochondrial haplotypes, with the major haplogroups T and I. The Bos taurus subhaplogroups consisted of T (3.3%), T1 (2.5%), T2 (2.5%), and T4 (0.8%) in addition to the predominant subhaplogroup T3 (86.9%), and the Bos indicus subhaplogroup of I1 (4.1%). Subsequently, we investigated the paternal lineages of Bos taurus and Bos indicus, however, all Kazakhstani cattle were shown to have Y chromosome of Bos taurus origin. While highly divergent mtDNA subhaplogroups in Kazakhstani cattle could be due to the geographical proximity of Kazakhstan with the domestication center of the Fertile Crescent, the absence of Bos indicus Y chromosomes could be explained by a decoupling of the introgression dynamics of maternal and paternal lineages. This genetic information would contribute to understanding the genetic diversity and propagation history of cattle in Central Asia.     

Clay minerals of red-yellow soils derived from pleistocene sediments in Japan

Red-Yellow soils are widely developed on terraces and hilly lands in the south-western half of Japan. They do not show any evidence of bleaching in the lower part of the A horizon, and are characterized by an extremely strong acid reaction, and a very low base-status⁹⁾. There are few studies on clay mineralogy of Red-Yellow soils in Japan. Egawa et al⁴⁾. have reported on clay mineralogy of soils derived from the Pleistocene and the Tertiary sediments most of which may be regarded as Red-Yellow soils. Matsui and Katô¹⁰⁾ have described clay minerals of Red-Yellow soils derived from the Pleistocene sediment in the environs of Shinjobara, Shizuoka Prefecture. These investigations indicated that clay minerals of Red-Yellow soils derived from the Pleistocene sediments consisted mainly of kaolin minerals, whereas those of Red-Yell ow soils derived from the Tertiary sediments were of the kaolin-illite association.     

Characterization of monoclonal antibodies against the second-generation schizonts of Leucocytozoon caulleryi

Monoclonal antibodies (MAbs), R1 and M5, were established against the second-generation schizont of Leucocytozoon caulleryi (L. caulleryi). Both antibodies reacted to membrane and internal structure proteins of the second-generation schizont by immunofluorescence microscopy. Molecular weight of the second-generation schizont (2GS) antigen was analyzed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. At least 40 protein bands were detected in 2GS antigen by SDS-PAGE under reduced condition and ranged from 10 to 270 kDa. MAb R1 reacted to polypeptides of 150-268 kDa in 2GS antigen, whereas MAb M5 did with that of 66 kDa. Injection with a protein of 2GS antigen fractionated by affinity chromatography using MAbs R1 and M5 protected chickens against challenge with sporozoites of L. caulleryi. These results suggest that MAbs, R1 and M5, recognize 2GS antigen of L caulleryi.     

Recovery mechanism of the antioxidant activity from carnosic acid quinone,an oxidized sage and rosemary antioxidant

A solution of carnosic acid quinone, which is a radical chain-termination product having no antioxidant activity in the antioxidant reaction of carnosic acid, recovers potent antioxidant activity upon standing. The HPLC analysis of an aged solution of carnosic acid quinone revealed that several antioxidants are produced in the solution. From the time-course and quantitative analyses of the formation of the products and their structural analysis, an antioxidant mechanism from carnosic acid quinone is proposed that includes a redox reaction of carnosic acid quinone in addition to the isomerization to lactone derivatives. In the first stage of antioxidation, carnosic acid, the reduction product from carnosic acid quinone, contributes to the potent antioxidant activity of the solution. This proposed mechanism can explain one of the reasons for the strong antioxidant activity of the extract of the popular herbs sage and rosemary.     

Predicting chronosequential changes in carbon stocks of pachymorph bamboo communities in slash-and-burn agricultural fallow,northern Lao People’s Democratic Republic

In northern Lao People’s Democratic Republic, rising human population has drastically reduced the fallow period of slash-and-burn agriculture which has led to a considerable decrease in the carbon stock in these communities. We estimated chronosequential changes in the communities' carbon stocks, and established the relationship between the fallow period and fallow-period-average carbon stocks in three carbon pools of bamboo-dominated communities in hilly areas of the Luang Prabang Province, northern Lao People’s Democratic Republic. Based on measurements by destructive sampling, we devised a model and root-to-shoot ratios for estimating bamboo biomass. In six secondary plant communities established after slash-and-burn cropping, we estimated community biomass using the above model and others, and measured deadwood and litter stocks. The communities’ biomass and deadwood significantly increased with time after the last cropping and the former reached about 100 Mg ha⁻¹ after 15 years, whereas litter stocks did not show significant trends over time. Extending the fallow period from 2 to 5 years would increase fallow-period-average carbon stock from 14.2 to 25.1 Mg C ha⁻¹. The overstory height was significantly correlated with biomass, deadwood, and litter carbon stocks of these communities. Based on our findings, changes in a community’s carbon stocks can be estimated using the changes in overstory height, which should be taken into account in future studies to reduce uncertainty in estimating carbon stocks in tropical ecosystems.