Cadmium adsorption on hydroxyaluminosilicate-montmorillonite complex as influenced by oxalate and citrate

The hydroxyaluminosilicate (HAS)-montmorillonite (Mt) and hydroxyaluminum (HyA)-Mt complexes are important constituents of soil colloidal complexes in acidic environments. Oxalate and citrate are dominant organic acids in the root exudates of many plants. These acids, among other factors, strongly influence the adsorption behavior of HAS-Mt and HyA-Mt complexes. In this study, we investigated the adsorption phenomena of Cd on the HAS-Mt and HyA-Mt complexes as influenced by oxalate and citrate. Without addition of oxalate and citrate, the adsorption of Cd on Mt was easy. However, in the presence of oxalate and citrate, the adsorption was strongly inhibited. In contrast, the HAS-Mt and HyA-Mt complexes in the absence of oxalate and citrate hardly adsorbed Cd. In the presence of oxalate, the HAS-Mt and HyA-Mt complexes were able to adsorb Cd. Thus, optimal concentration of oxalate for Cd adsorption on both complexes could be determined. Similarly, the HyA-Mt complex showed an optimal concentration of citrate for Cd adsorption. However, the HAS-Mt complex did not adsorb Cd in the presence of citrate. We concluded that the optimal concentrations of oxalate and citrate for Cd adsorption depended on the form of Cd ions and their proportion in the solution. Based on the amount of Cd adsorbed and the distribution of Cd species in the solution, the adsorption of Cd on the HAS-Mt and HyA-Mt complexes took place in various chemical forms.     

Allelic frequencies and association with carcass traits of six genes in local subpopulations of Japanese Black cattle

Marker‐assisted selection (MAS) is expected to accelerate the genetic improvement of Japanese Black cattle. However, verification of the effects of the genes for MAS in different subpopulations is required prior to the application of MAS. In this study, we investigated the allelic frequencies and genotypic effects for carcass traits of six genes, which can be used in MAS, in eight local subpopulations. These genes are SCD, FASN and SREBP1, which are associated with the fatty acid composition of meat, and NCAPG, MC1R and F11, which are associated with carcass weight, coat color and blood coagulation abnormality, respectively. The frequencies of desirable alleles of SCD and FASN were relatively high and that of NCAPG was relatively low, and NCAPG was significantly associated with several carcass traits, including carcass weight. The proportions of genotypic variance explained by NCAPG to phenotypic variance were 4.83 for carcass weight. We thus confirmed that NCAPG is a useful marker for selection of carcass traits in these subpopulations. In addition, we found that the desirable alleles of six genes showed no negative effects on carcass traits. Therefore, selection using these genes to improve target traits should not have negative impacts on carcass traits.     

Induced response of the Siebold's beech (Fagus crenata Blume) to manual defoliation

Siebold's beech (Fagus crenata) was manually defoliated for two successive years. The beech caterpillar (Quadricalcarifera punctatella) was used in a bioassay to determine insect performance. Survival and body size were low on foliage from defoliated trees. Reduced foliar nitrogen and increased tannin content were probably the main causes of the low insect performance. Leaves were less tough on defoliated trees than in controls. Two sucessive years of manual defoliation caused stronger induced resistance than one year defoliation. The quality, as well as the quality of the foliage, decreased the year following manual defoliation; total weight of leaves on a tree was less than one half of that before treatment. Severe defoliation may cause a decrease of leaves the following year and starvation may limit populations. Delayed induced resistance of beech trees is proposed as a possible cause of the cyclical population dynamics ofQ. punctatella. The delayed induced response also affected folivorous insects other thanQ. punctatella.     

Analysis of load-slip characteristics of nailed wood joints: application of a two-dimensional geometric nonlinear analysis

We used a two-dimensional finite element method to analyze the load-slip characteristics of nailed wooden joints sheathed with a panel. We used tests of nail bending, nail shank embedment in a wood or a panel, nail-head embedment in a face of a panel, nail withdrawing from a wood, friction between a wood and a panel, and initial axial forces of the nails. The values of the material properties for the analytical models were determined with the above tests. With a conventional one-dimensional analysis it is impossible to evaluate the shearing performance accurately because the axial forces of the nail are not calculated. Therefore, we used two-dimensional geometric nonlinear analysis. The computed load-slip curves closely matched the original experimental results; and when the friction and initial axial forces were considered, the computed curves were more likely to match the original experimental results. Our results suggested that it is better to use geometric nonlinear analysis to analyze the shearing characteristics of nailed joints, and that friction and axial forces are important factors for accurate analysis.Parts of this report were presented at the 7th World Conference on Timber Engineering, Malaysia, August 2002     

Virtual forest: design and evaluation of a walk-through system for forest education

Forest education is generally conducted in a real forest to provide learners a direct experience with reality. However, often it is not easy to participate in forest education programs carried out in remote places due to distance, limited time, or economic or physical restrictions. Therefore, we developed a walk-through system for forest education in a virtual forest and evaluated its educational efficacy as well as usability through indoor experiments. The virtual forest was constructed with omnidirectional images taken in a forest using a digital camera with an omnidirectional vision sensor. The results of the postquestionnaire showed that the developed system was highly evaluated by the participants in the experiments in terms of educational efficacy and enjoyment. Also, comparison of results of prequestionnaire and postquestionnaire showed that it had educational value. On the other hand, some technical problems in the developed system were revealed. For example, 45.0% of the participants answered that the walk-through in the virtual forest did not proceed with sufficient smoothness, and encountered unexpected slowdowns and stops. In addition, image quality was not high enough to identify small objects in the virtual forest. Regardless of these problems, we believe that the computer-based forest education was successful because 88.3% of the participants answered that they would like to join a similar program again and 90.0% answered that they would like to visit the real forest that the virtual forest imitated.     

Influence of Mercury on Soybean Plants (Glycine max L.) at Low pH

The influence of Hg on soybean plants under different pH conditions and Hg concentrations was studied. Growth inhibition by Hg was higher in roots than the upper part of the plant, but was highly dependant on pH condition. Growth inhibition of roots was observed when Hg concentration was higher than 1 mg Hg L⁻¹ for pH 4.0 and 5 mg Hg L⁻¹ for pH 6.0. Using ²⁰³Hg as a radioactive tracer, the amount of Hg (1 mg Hg L⁻¹) uptake in root was found to be about 1.5 times higher at pH 4.0 than that at pH 6.0; suggesting that Hg when highly accumulated at the lower pH induced inhibition of root growth. Decreased amounts of Hg due to evaporation during the plant growth were very low, but were higher at pH 6.0 than that at pH 4.0. There was hardly any translocation of Hg from roots to the upper parts through the stem within 24 h.     

Identification of anthocyanins in the sprouts of buckwheat

The anthocyanin profiles and varieties/breeding line differences of anthocyanin concentrations in common/tartary buckwheat sprouts have been studied. Four anthocyanins, cyanidin 3-O-glucoside, cyanidin 3-O-rutinoside, cyanidin 3-O-galactoside, and cyanidin 3-O-galactopyranosyl-rhamnoside, were isolated from the sprouts of common buckwheat, were separated using high-performance liquid chromatography (HPLC), and were identified using reversed-phase liquid chromatography (LC)/electrospray ionization-mass spectrometry (ESI-MS)/MS techniques. In tartary buckwheat sprouts, two anthocyanins (cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside) were identified. Among 19 common/tartary buckwheat varieties/breeding lines, Hokkai T10 contained the highest amounts of anthocyanins. Cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside concentrations in 6-10 days after seeding sprouts of Hokkai T10 ranged from 0.16 to 0.20 mg/g dry wt and from 5.55 to 6.57 mg/g dry wt, respectively. In addition, dark-grown sprouts of Hokkai T10 accumulated 0.091 and 2.77 mg/g dry wt of cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside whereas other varieties/breeding lines accumulated trace amounts of anthocyanins. Given its anthocyanin-rich red cotyledons, Hokkai T10 is a promising line for use as "Moyashi" type sprouts and is strongly recommended as a new functional food, rich in dietary anthocyanins.     

Novel capsid genes (g23) of T4-type bacteriophages in a Japanese paddy field

Viruses exist everywhere on the planet. Recent development in viral genomics confirmed that genomic information is preserved among viral subsets and can be used for phylogenetic classification of viruses and for evaluation of viral diversity in the environment. The capsid gene of T4-type bacteriophages, g23, is the most widely applied gene for evaluating the diversity of the T4-type bacteriophage family. In this study, we applied denaturing gradient gel electrophoresis to PCR products of DNA with g23-specific primers that were extracted from a Japanese paddy field under long-term fertilizer trial and obtained 39 different g23 clones at the DNA level. They showed identities of 27–99% with the clones within the NCBI database at the amino acid level. They were quite distinctive from those obtained in marine environments and most of them formed six phylogenetically novel groups in the T4-type bacteriophage family with the clones obtained from another paddy field. The existence of six novel groups was confirmed from molecular analysis of all the amino acid sequences between the primers, of the amino acid sequences excluding hypervariable region, and of those of conserved regions. These findings indicate that T4-type bacteriophage communities in paddy fields consist of previously uncharacterized members phylogenetically distant from those in marine environments. The type of fertilizers and the stage during rice cultivation were not the major factors in determining T4-type bacteriophage communities in the paddy field.     

Toe white line separation associated with the notch (crena marginalis) on the distal phalanges in Thoroughbred yearling horses

The shape of the white line of the hoof is closely related to the shape of the notch on the dorsal distal bearing border of the distal phalanx (P3). In this study, a radiographic survey of the P3 of both forelimbs of 163 Thoroughbred yearling horses was conducted. The correlation of the depth and width of the notch were analyzed with the toe white line separation grades (0 to 3). As a result, the toe white line separation grade increased, the depth and the width of the notch also increased significantly. Radiographic examination of the P3 of the forelimbs might be useful for deciding whether to implement hoof care to prevent onset of toe white line separation.     

Coleoptile cuticle of barley is necessary for the increase in appressorial turgor pressure of <Emphasis Type="Italic">Blumeria graminis</Emphasis> for penetration

To determine whether the cuticle of the barley coleoptile is responsible for a rise in appressorial turgor pressure in Blumeria graminis, we determined the appressorial turgor pressure by measuring cytorrhysis and plasmolysis in the presence of PEG6000. Appressorial turgor pressure significantly increased 13–14 h after inoculation. On the other hand, when the cuticle was completely removed from the barley coleoptile surface with diethyl ether, turgor pressure did not increase. Moreover, when we then recoated the surface with the exogenous barley cuticle fraction, appressorial turgor pressure significantly increased 12–13 h after inoculation. These results suggest that the cuticle on the surface of the barley coleoptile is necessary for the increase in the appressorial turgor pressure.